diff --git a/CHANGELOG.md b/CHANGELOG.md
index 23e7b13a04..b8e37e669d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,7 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 
 ### Changed
 
-- Nothing.
+- Updated the CONVERT() function to support all current MS Excel categories and Units of Measure.
 
 ### Deprecated
 
diff --git a/src/PhpSpreadsheet/Calculation/Engineering.php b/src/PhpSpreadsheet/Calculation/Engineering.php
index 1256dd90be..57116f28f5 100644
--- a/src/PhpSpreadsheet/Calculation/Engineering.php
+++ b/src/PhpSpreadsheet/Calculation/Engineering.php
@@ -4,6 +4,7 @@
 
 use Complex\Complex;
 use Complex\Exception as ComplexException;
+use PhpOffice\PhpSpreadsheet\Calculation\Engineering\ConvertUOM;
 
 class Engineering
 {
@@ -12,710 +13,6 @@ class Engineering
      */
     const EULER = 2.71828182845904523536;
 
-    /**
-     * Details of the Units of measure that can be used in CONVERTUOM().
-     *
-     * @var mixed[]
-     */
-    private static $conversionUnits = [
-        'g' => ['Group' => 'Mass', 'Unit Name' => 'Gram', 'AllowPrefix' => true],
-        'sg' => ['Group' => 'Mass', 'Unit Name' => 'Slug', 'AllowPrefix' => false],
-        'lbm' => ['Group' => 'Mass', 'Unit Name' => 'Pound mass (avoirdupois)', 'AllowPrefix' => false],
-        'u' => ['Group' => 'Mass', 'Unit Name' => 'U (atomic mass unit)', 'AllowPrefix' => true],
-        'ozm' => ['Group' => 'Mass', 'Unit Name' => 'Ounce mass (avoirdupois)', 'AllowPrefix' => false],
-        'm' => ['Group' => 'Distance', 'Unit Name' => 'Meter', 'AllowPrefix' => true],
-        'mi' => ['Group' => 'Distance', 'Unit Name' => 'Statute mile', 'AllowPrefix' => false],
-        'Nmi' => ['Group' => 'Distance', 'Unit Name' => 'Nautical mile', 'AllowPrefix' => false],
-        'in' => ['Group' => 'Distance', 'Unit Name' => 'Inch', 'AllowPrefix' => false],
-        'ft' => ['Group' => 'Distance', 'Unit Name' => 'Foot', 'AllowPrefix' => false],
-        'yd' => ['Group' => 'Distance', 'Unit Name' => 'Yard', 'AllowPrefix' => false],
-        'ang' => ['Group' => 'Distance', 'Unit Name' => 'Angstrom', 'AllowPrefix' => true],
-        'Pica' => ['Group' => 'Distance', 'Unit Name' => 'Pica (1/72 in)', 'AllowPrefix' => false],
-        'yr' => ['Group' => 'Time', 'Unit Name' => 'Year', 'AllowPrefix' => false],
-        'day' => ['Group' => 'Time', 'Unit Name' => 'Day', 'AllowPrefix' => false],
-        'hr' => ['Group' => 'Time', 'Unit Name' => 'Hour', 'AllowPrefix' => false],
-        'mn' => ['Group' => 'Time', 'Unit Name' => 'Minute', 'AllowPrefix' => false],
-        'sec' => ['Group' => 'Time', 'Unit Name' => 'Second', 'AllowPrefix' => true],
-        'Pa' => ['Group' => 'Pressure', 'Unit Name' => 'Pascal', 'AllowPrefix' => true],
-        'p' => ['Group' => 'Pressure', 'Unit Name' => 'Pascal', 'AllowPrefix' => true],
-        'atm' => ['Group' => 'Pressure', 'Unit Name' => 'Atmosphere', 'AllowPrefix' => true],
-        'at' => ['Group' => 'Pressure', 'Unit Name' => 'Atmosphere', 'AllowPrefix' => true],
-        'mmHg' => ['Group' => 'Pressure', 'Unit Name' => 'mm of Mercury', 'AllowPrefix' => true],
-        'N' => ['Group' => 'Force', 'Unit Name' => 'Newton', 'AllowPrefix' => true],
-        'dyn' => ['Group' => 'Force', 'Unit Name' => 'Dyne', 'AllowPrefix' => true],
-        'dy' => ['Group' => 'Force', 'Unit Name' => 'Dyne', 'AllowPrefix' => true],
-        'lbf' => ['Group' => 'Force', 'Unit Name' => 'Pound force', 'AllowPrefix' => false],
-        'J' => ['Group' => 'Energy', 'Unit Name' => 'Joule', 'AllowPrefix' => true],
-        'e' => ['Group' => 'Energy', 'Unit Name' => 'Erg', 'AllowPrefix' => true],
-        'c' => ['Group' => 'Energy', 'Unit Name' => 'Thermodynamic calorie', 'AllowPrefix' => true],
-        'cal' => ['Group' => 'Energy', 'Unit Name' => 'IT calorie', 'AllowPrefix' => true],
-        'eV' => ['Group' => 'Energy', 'Unit Name' => 'Electron volt', 'AllowPrefix' => true],
-        'ev' => ['Group' => 'Energy', 'Unit Name' => 'Electron volt', 'AllowPrefix' => true],
-        'HPh' => ['Group' => 'Energy', 'Unit Name' => 'Horsepower-hour', 'AllowPrefix' => false],
-        'hh' => ['Group' => 'Energy', 'Unit Name' => 'Horsepower-hour', 'AllowPrefix' => false],
-        'Wh' => ['Group' => 'Energy', 'Unit Name' => 'Watt-hour', 'AllowPrefix' => true],
-        'wh' => ['Group' => 'Energy', 'Unit Name' => 'Watt-hour', 'AllowPrefix' => true],
-        'flb' => ['Group' => 'Energy', 'Unit Name' => 'Foot-pound', 'AllowPrefix' => false],
-        'BTU' => ['Group' => 'Energy', 'Unit Name' => 'BTU', 'AllowPrefix' => false],
-        'btu' => ['Group' => 'Energy', 'Unit Name' => 'BTU', 'AllowPrefix' => false],
-        'HP' => ['Group' => 'Power', 'Unit Name' => 'Horsepower', 'AllowPrefix' => false],
-        'h' => ['Group' => 'Power', 'Unit Name' => 'Horsepower', 'AllowPrefix' => false],
-        'W' => ['Group' => 'Power', 'Unit Name' => 'Watt', 'AllowPrefix' => true],
-        'w' => ['Group' => 'Power', 'Unit Name' => 'Watt', 'AllowPrefix' => true],
-        'T' => ['Group' => 'Magnetism', 'Unit Name' => 'Tesla', 'AllowPrefix' => true],
-        'ga' => ['Group' => 'Magnetism', 'Unit Name' => 'Gauss', 'AllowPrefix' => true],
-        'C' => ['Group' => 'Temperature', 'Unit Name' => 'Celsius', 'AllowPrefix' => false],
-        'cel' => ['Group' => 'Temperature', 'Unit Name' => 'Celsius', 'AllowPrefix' => false],
-        'F' => ['Group' => 'Temperature', 'Unit Name' => 'Fahrenheit', 'AllowPrefix' => false],
-        'fah' => ['Group' => 'Temperature', 'Unit Name' => 'Fahrenheit', 'AllowPrefix' => false],
-        'K' => ['Group' => 'Temperature', 'Unit Name' => 'Kelvin', 'AllowPrefix' => false],
-        'kel' => ['Group' => 'Temperature', 'Unit Name' => 'Kelvin', 'AllowPrefix' => false],
-        'tsp' => ['Group' => 'Liquid', 'Unit Name' => 'Teaspoon', 'AllowPrefix' => false],
-        'tbs' => ['Group' => 'Liquid', 'Unit Name' => 'Tablespoon', 'AllowPrefix' => false],
-        'oz' => ['Group' => 'Liquid', 'Unit Name' => 'Fluid Ounce', 'AllowPrefix' => false],
-        'cup' => ['Group' => 'Liquid', 'Unit Name' => 'Cup', 'AllowPrefix' => false],
-        'pt' => ['Group' => 'Liquid', 'Unit Name' => 'U.S. Pint', 'AllowPrefix' => false],
-        'us_pt' => ['Group' => 'Liquid', 'Unit Name' => 'U.S. Pint', 'AllowPrefix' => false],
-        'uk_pt' => ['Group' => 'Liquid', 'Unit Name' => 'U.K. Pint', 'AllowPrefix' => false],
-        'qt' => ['Group' => 'Liquid', 'Unit Name' => 'Quart', 'AllowPrefix' => false],
-        'gal' => ['Group' => 'Liquid', 'Unit Name' => 'Gallon', 'AllowPrefix' => false],
-        'l' => ['Group' => 'Liquid', 'Unit Name' => 'Litre', 'AllowPrefix' => true],
-        'lt' => ['Group' => 'Liquid', 'Unit Name' => 'Litre', 'AllowPrefix' => true],
-    ];
-
-    /**
-     * Details of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM().
-     *
-     * @var mixed[]
-     */
-    private static $conversionMultipliers = [
-        'Y' => ['multiplier' => 1E24, 'name' => 'yotta'],
-        'Z' => ['multiplier' => 1E21, 'name' => 'zetta'],
-        'E' => ['multiplier' => 1E18, 'name' => 'exa'],
-        'P' => ['multiplier' => 1E15, 'name' => 'peta'],
-        'T' => ['multiplier' => 1E12, 'name' => 'tera'],
-        'G' => ['multiplier' => 1E9, 'name' => 'giga'],
-        'M' => ['multiplier' => 1E6, 'name' => 'mega'],
-        'k' => ['multiplier' => 1E3, 'name' => 'kilo'],
-        'h' => ['multiplier' => 1E2, 'name' => 'hecto'],
-        'e' => ['multiplier' => 1E1, 'name' => 'deka'],
-        'd' => ['multiplier' => 1E-1, 'name' => 'deci'],
-        'c' => ['multiplier' => 1E-2, 'name' => 'centi'],
-        'm' => ['multiplier' => 1E-3, 'name' => 'milli'],
-        'u' => ['multiplier' => 1E-6, 'name' => 'micro'],
-        'n' => ['multiplier' => 1E-9, 'name' => 'nano'],
-        'p' => ['multiplier' => 1E-12, 'name' => 'pico'],
-        'f' => ['multiplier' => 1E-15, 'name' => 'femto'],
-        'a' => ['multiplier' => 1E-18, 'name' => 'atto'],
-        'z' => ['multiplier' => 1E-21, 'name' => 'zepto'],
-        'y' => ['multiplier' => 1E-24, 'name' => 'yocto'],
-    ];
-
-    /**
-     * Details of the Units of measure conversion factors, organised by group.
-     *
-     * @var mixed[]
-     */
-    private static $unitConversions = [
-        'Mass' => [
-            'g' => [
-                'g' => 1.0,
-                'sg' => 6.85220500053478E-05,
-                'lbm' => 2.20462291469134E-03,
-                'u' => 6.02217000000000E+23,
-                'ozm' => 3.52739718003627E-02,
-            ],
-            'sg' => [
-                'g' => 1.45938424189287E+04,
-                'sg' => 1.0,
-                'lbm' => 3.21739194101647E+01,
-                'u' => 8.78866000000000E+27,
-                'ozm' => 5.14782785944229E+02,
-            ],
-            'lbm' => [
-                'g' => 4.5359230974881148E+02,
-                'sg' => 3.10810749306493E-02,
-                'lbm' => 1.0,
-                'u' => 2.73161000000000E+26,
-                'ozm' => 1.60000023429410E+01,
-            ],
-            'u' => [
-                'g' => 1.66053100460465E-24,
-                'sg' => 1.13782988532950E-28,
-                'lbm' => 3.66084470330684E-27,
-                'u' => 1.0,
-                'ozm' => 5.85735238300524E-26,
-            ],
-            'ozm' => [
-                'g' => 2.83495152079732E+01,
-                'sg' => 1.94256689870811E-03,
-                'lbm' => 6.24999908478882E-02,
-                'u' => 1.70725600000000E+25,
-                'ozm' => 1.0,
-            ],
-        ],
-        'Distance' => [
-            'm' => [
-                'm' => 1.0,
-                'mi' => 6.21371192237334E-04,
-                'Nmi' => 5.39956803455724E-04,
-                'in' => 3.93700787401575E+01,
-                'ft' => 3.28083989501312E+00,
-                'yd' => 1.09361329797891E+00,
-                'ang' => 1.00000000000000E+10,
-                'Pica' => 2.83464566929116E+03,
-            ],
-            'mi' => [
-                'm' => 1.60934400000000E+03,
-                'mi' => 1.0,
-                'Nmi' => 8.68976241900648E-01,
-                'in' => 6.33600000000000E+04,
-                'ft' => 5.28000000000000E+03,
-                'yd' => 1.76000000000000E+03,
-                'ang' => 1.60934400000000E+13,
-                'Pica' => 4.56191999999971E+06,
-            ],
-            'Nmi' => [
-                'm' => 1.85200000000000E+03,
-                'mi' => 1.15077944802354E+00,
-                'Nmi' => 1.0,
-                'in' => 7.29133858267717E+04,
-                'ft' => 6.07611548556430E+03,
-                'yd' => 2.02537182785694E+03,
-                'ang' => 1.85200000000000E+13,
-                'Pica' => 5.24976377952723E+06,
-            ],
-            'in' => [
-                'm' => 2.54000000000000E-02,
-                'mi' => 1.57828282828283E-05,
-                'Nmi' => 1.37149028077754E-05,
-                'in' => 1.0,
-                'ft' => 8.33333333333333E-02,
-                'yd' => 2.77777777686643E-02,
-                'ang' => 2.54000000000000E+08,
-                'Pica' => 7.19999999999955E+01,
-            ],
-            'ft' => [
-                'm' => 3.04800000000000E-01,
-                'mi' => 1.89393939393939E-04,
-                'Nmi' => 1.64578833693305E-04,
-                'in' => 1.20000000000000E+01,
-                'ft' => 1.0,
-                'yd' => 3.33333333223972E-01,
-                'ang' => 3.04800000000000E+09,
-                'Pica' => 8.63999999999946E+02,
-            ],
-            'yd' => [
-                'm' => 9.14400000300000E-01,
-                'mi' => 5.68181818368230E-04,
-                'Nmi' => 4.93736501241901E-04,
-                'in' => 3.60000000118110E+01,
-                'ft' => 3.00000000000000E+00,
-                'yd' => 1.0,
-                'ang' => 9.14400000300000E+09,
-                'Pica' => 2.59200000085023E+03,
-            ],
-            'ang' => [
-                'm' => 1.00000000000000E-10,
-                'mi' => 6.21371192237334E-14,
-                'Nmi' => 5.39956803455724E-14,
-                'in' => 3.93700787401575E-09,
-                'ft' => 3.28083989501312E-10,
-                'yd' => 1.09361329797891E-10,
-                'ang' => 1.0,
-                'Pica' => 2.83464566929116E-07,
-            ],
-            'Pica' => [
-                'm' => 3.52777777777800E-04,
-                'mi' => 2.19205948372629E-07,
-                'Nmi' => 1.90484761219114E-07,
-                'in' => 1.38888888888898E-02,
-                'ft' => 1.15740740740748E-03,
-                'yd' => 3.85802469009251E-04,
-                'ang' => 3.52777777777800E+06,
-                'Pica' => 1.0,
-            ],
-        ],
-        'Time' => [
-            'yr' => [
-                'yr' => 1.0,
-                'day' => 365.25,
-                'hr' => 8766.0,
-                'mn' => 525960.0,
-                'sec' => 31557600.0,
-            ],
-            'day' => [
-                'yr' => 2.73785078713210E-03,
-                'day' => 1.0,
-                'hr' => 24.0,
-                'mn' => 1440.0,
-                'sec' => 86400.0,
-            ],
-            'hr' => [
-                'yr' => 1.14077116130504E-04,
-                'day' => 4.16666666666667E-02,
-                'hr' => 1.0,
-                'mn' => 60.0,
-                'sec' => 3600.0,
-            ],
-            'mn' => [
-                'yr' => 1.90128526884174E-06,
-                'day' => 6.94444444444444E-04,
-                'hr' => 1.66666666666667E-02,
-                'mn' => 1.0,
-                'sec' => 60.0,
-            ],
-            'sec' => [
-                'yr' => 3.16880878140289E-08,
-                'day' => 1.15740740740741E-05,
-                'hr' => 2.77777777777778E-04,
-                'mn' => 1.66666666666667E-02,
-                'sec' => 1.0,
-            ],
-        ],
-        'Pressure' => [
-            'Pa' => [
-                'Pa' => 1.0,
-                'p' => 1.0,
-                'atm' => 9.86923299998193E-06,
-                'at' => 9.86923299998193E-06,
-                'mmHg' => 7.50061707998627E-03,
-            ],
-            'p' => [
-                'Pa' => 1.0,
-                'p' => 1.0,
-                'atm' => 9.86923299998193E-06,
-                'at' => 9.86923299998193E-06,
-                'mmHg' => 7.50061707998627E-03,
-            ],
-            'atm' => [
-                'Pa' => 1.01324996583000E+05,
-                'p' => 1.01324996583000E+05,
-                'atm' => 1.0,
-                'at' => 1.0,
-                'mmHg' => 760.0,
-            ],
-            'at' => [
-                'Pa' => 1.01324996583000E+05,
-                'p' => 1.01324996583000E+05,
-                'atm' => 1.0,
-                'at' => 1.0,
-                'mmHg' => 760.0,
-            ],
-            'mmHg' => [
-                'Pa' => 1.33322363925000E+02,
-                'p' => 1.33322363925000E+02,
-                'atm' => 1.31578947368421E-03,
-                'at' => 1.31578947368421E-03,
-                'mmHg' => 1.0,
-            ],
-        ],
-        'Force' => [
-            'N' => [
-                'N' => 1.0,
-                'dyn' => 1.0E+5,
-                'dy' => 1.0E+5,
-                'lbf' => 2.24808923655339E-01,
-            ],
-            'dyn' => [
-                'N' => 1.0E-5,
-                'dyn' => 1.0,
-                'dy' => 1.0,
-                'lbf' => 2.24808923655339E-06,
-            ],
-            'dy' => [
-                'N' => 1.0E-5,
-                'dyn' => 1.0,
-                'dy' => 1.0,
-                'lbf' => 2.24808923655339E-06,
-            ],
-            'lbf' => [
-                'N' => 4.448222,
-                'dyn' => 4.448222E+5,
-                'dy' => 4.448222E+5,
-                'lbf' => 1.0,
-            ],
-        ],
-        'Energy' => [
-            'J' => [
-                'J' => 1.0,
-                'e' => 9.99999519343231E+06,
-                'c' => 2.39006249473467E-01,
-                'cal' => 2.38846190642017E-01,
-                'eV' => 6.24145700000000E+18,
-                'ev' => 6.24145700000000E+18,
-                'HPh' => 3.72506430801000E-07,
-                'hh' => 3.72506430801000E-07,
-                'Wh' => 2.77777916238711E-04,
-                'wh' => 2.77777916238711E-04,
-                'flb' => 2.37304222192651E+01,
-                'BTU' => 9.47815067349015E-04,
-                'btu' => 9.47815067349015E-04,
-            ],
-            'e' => [
-                'J' => 1.00000048065700E-07,
-                'e' => 1.0,
-                'c' => 2.39006364353494E-08,
-                'cal' => 2.38846305445111E-08,
-                'eV' => 6.24146000000000E+11,
-                'ev' => 6.24146000000000E+11,
-                'HPh' => 3.72506609848824E-14,
-                'hh' => 3.72506609848824E-14,
-                'Wh' => 2.77778049754611E-11,
-                'wh' => 2.77778049754611E-11,
-                'flb' => 2.37304336254586E-06,
-                'BTU' => 9.47815522922962E-11,
-                'btu' => 9.47815522922962E-11,
-            ],
-            'c' => [
-                'J' => 4.18399101363672E+00,
-                'e' => 4.18398900257312E+07,
-                'c' => 1.0,
-                'cal' => 9.99330315287563E-01,
-                'eV' => 2.61142000000000E+19,
-                'ev' => 2.61142000000000E+19,
-                'HPh' => 1.55856355899327E-06,
-                'hh' => 1.55856355899327E-06,
-                'Wh' => 1.16222030532950E-03,
-                'wh' => 1.16222030532950E-03,
-                'flb' => 9.92878733152102E+01,
-                'BTU' => 3.96564972437776E-03,
-                'btu' => 3.96564972437776E-03,
-            ],
-            'cal' => [
-                'J' => 4.18679484613929E+00,
-                'e' => 4.18679283372801E+07,
-                'c' => 1.00067013349059E+00,
-                'cal' => 1.0,
-                'eV' => 2.61317000000000E+19,
-                'ev' => 2.61317000000000E+19,
-                'HPh' => 1.55960800463137E-06,
-                'hh' => 1.55960800463137E-06,
-                'Wh' => 1.16299914807955E-03,
-                'wh' => 1.16299914807955E-03,
-                'flb' => 9.93544094443283E+01,
-                'BTU' => 3.96830723907002E-03,
-                'btu' => 3.96830723907002E-03,
-            ],
-            'eV' => [
-                'J' => 1.60219000146921E-19,
-                'e' => 1.60218923136574E-12,
-                'c' => 3.82933423195043E-20,
-                'cal' => 3.82676978535648E-20,
-                'eV' => 1.0,
-                'ev' => 1.0,
-                'HPh' => 5.96826078912344E-26,
-                'hh' => 5.96826078912344E-26,
-                'Wh' => 4.45053000026614E-23,
-                'wh' => 4.45053000026614E-23,
-                'flb' => 3.80206452103492E-18,
-                'BTU' => 1.51857982414846E-22,
-                'btu' => 1.51857982414846E-22,
-            ],
-            'ev' => [
-                'J' => 1.60219000146921E-19,
-                'e' => 1.60218923136574E-12,
-                'c' => 3.82933423195043E-20,
-                'cal' => 3.82676978535648E-20,
-                'eV' => 1.0,
-                'ev' => 1.0,
-                'HPh' => 5.96826078912344E-26,
-                'hh' => 5.96826078912344E-26,
-                'Wh' => 4.45053000026614E-23,
-                'wh' => 4.45053000026614E-23,
-                'flb' => 3.80206452103492E-18,
-                'BTU' => 1.51857982414846E-22,
-                'btu' => 1.51857982414846E-22,
-            ],
-            'HPh' => [
-                'J' => 2.68451741316170E+06,
-                'e' => 2.68451612283024E+13,
-                'c' => 6.41616438565991E+05,
-                'cal' => 6.41186757845835E+05,
-                'eV' => 1.67553000000000E+25,
-                'ev' => 1.67553000000000E+25,
-                'HPh' => 1.0,
-                'hh' => 1.0,
-                'Wh' => 7.45699653134593E+02,
-                'wh' => 7.45699653134593E+02,
-                'flb' => 6.37047316692964E+07,
-                'BTU' => 2.54442605275546E+03,
-                'btu' => 2.54442605275546E+03,
-            ],
-            'hh' => [
-                'J' => 2.68451741316170E+06,
-                'e' => 2.68451612283024E+13,
-                'c' => 6.41616438565991E+05,
-                'cal' => 6.41186757845835E+05,
-                'eV' => 1.67553000000000E+25,
-                'ev' => 1.67553000000000E+25,
-                'HPh' => 1.0,
-                'hh' => 1.0,
-                'Wh' => 7.45699653134593E+02,
-                'wh' => 7.45699653134593E+02,
-                'flb' => 6.37047316692964E+07,
-                'BTU' => 2.54442605275546E+03,
-                'btu' => 2.54442605275546E+03,
-            ],
-            'Wh' => [
-                'J' => 3.59999820554720E+03,
-                'e' => 3.59999647518369E+10,
-                'c' => 8.60422069219046E+02,
-                'cal' => 8.59845857713046E+02,
-                'eV' => 2.24692340000000E+22,
-                'ev' => 2.24692340000000E+22,
-                'HPh' => 1.34102248243839E-03,
-                'hh' => 1.34102248243839E-03,
-                'Wh' => 1.0,
-                'wh' => 1.0,
-                'flb' => 8.54294774062316E+04,
-                'BTU' => 3.41213254164705E+00,
-                'btu' => 3.41213254164705E+00,
-            ],
-            'wh' => [
-                'J' => 3.59999820554720E+03,
-                'e' => 3.59999647518369E+10,
-                'c' => 8.60422069219046E+02,
-                'cal' => 8.59845857713046E+02,
-                'eV' => 2.24692340000000E+22,
-                'ev' => 2.24692340000000E+22,
-                'HPh' => 1.34102248243839E-03,
-                'hh' => 1.34102248243839E-03,
-                'Wh' => 1.0,
-                'wh' => 1.0,
-                'flb' => 8.54294774062316E+04,
-                'BTU' => 3.41213254164705E+00,
-                'btu' => 3.41213254164705E+00,
-            ],
-            'flb' => [
-                'J' => 4.21400003236424E-02,
-                'e' => 4.21399800687660E+05,
-                'c' => 1.00717234301644E-02,
-                'cal' => 1.00649785509554E-02,
-                'eV' => 2.63015000000000E+17,
-                'ev' => 2.63015000000000E+17,
-                'HPh' => 1.56974211145130E-08,
-                'hh' => 1.56974211145130E-08,
-                'Wh' => 1.17055614802000E-05,
-                'wh' => 1.17055614802000E-05,
-                'flb' => 1.0,
-                'BTU' => 3.99409272448406E-05,
-                'btu' => 3.99409272448406E-05,
-            ],
-            'BTU' => [
-                'J' => 1.05505813786749E+03,
-                'e' => 1.05505763074665E+10,
-                'c' => 2.52165488508168E+02,
-                'cal' => 2.51996617135510E+02,
-                'eV' => 6.58510000000000E+21,
-                'ev' => 6.58510000000000E+21,
-                'HPh' => 3.93015941224568E-04,
-                'hh' => 3.93015941224568E-04,
-                'Wh' => 2.93071851047526E-01,
-                'wh' => 2.93071851047526E-01,
-                'flb' => 2.50369750774671E+04,
-                'BTU' => 1.0,
-                'btu' => 1.0,
-            ],
-            'btu' => [
-                'J' => 1.05505813786749E+03,
-                'e' => 1.05505763074665E+10,
-                'c' => 2.52165488508168E+02,
-                'cal' => 2.51996617135510E+02,
-                'eV' => 6.58510000000000E+21,
-                'ev' => 6.58510000000000E+21,
-                'HPh' => 3.93015941224568E-04,
-                'hh' => 3.93015941224568E-04,
-                'Wh' => 2.93071851047526E-01,
-                'wh' => 2.93071851047526E-01,
-                'flb' => 2.50369750774671E+04,
-                'BTU' => 1.0,
-                'btu' => 1.0,
-            ],
-        ],
-        'Power' => [
-            'HP' => [
-                'HP' => 1.0,
-                'h' => 1.0,
-                'W' => 7.45701000000000E+02,
-                'w' => 7.45701000000000E+02,
-            ],
-            'h' => [
-                'HP' => 1.0,
-                'h' => 1.0,
-                'W' => 7.45701000000000E+02,
-                'w' => 7.45701000000000E+02,
-            ],
-            'W' => [
-                'HP' => 1.34102006031908E-03,
-                'h' => 1.34102006031908E-03,
-                'W' => 1.0,
-                'w' => 1.0,
-            ],
-            'w' => [
-                'HP' => 1.34102006031908E-03,
-                'h' => 1.34102006031908E-03,
-                'W' => 1.0,
-                'w' => 1.0,
-            ],
-        ],
-        'Magnetism' => [
-            'T' => [
-                'T' => 1.0,
-                'ga' => 10000.0,
-            ],
-            'ga' => [
-                'T' => 0.0001,
-                'ga' => 1.0,
-            ],
-        ],
-        'Liquid' => [
-            'tsp' => [
-                'tsp' => 1.0,
-                'tbs' => 3.33333333333333E-01,
-                'oz' => 1.66666666666667E-01,
-                'cup' => 2.08333333333333E-02,
-                'pt' => 1.04166666666667E-02,
-                'us_pt' => 1.04166666666667E-02,
-                'uk_pt' => 8.67558516821960E-03,
-                'qt' => 5.20833333333333E-03,
-                'gal' => 1.30208333333333E-03,
-                'l' => 4.92999408400710E-03,
-                'lt' => 4.92999408400710E-03,
-            ],
-            'tbs' => [
-                'tsp' => 3.00000000000000E+00,
-                'tbs' => 1.0,
-                'oz' => 5.00000000000000E-01,
-                'cup' => 6.25000000000000E-02,
-                'pt' => 3.12500000000000E-02,
-                'us_pt' => 3.12500000000000E-02,
-                'uk_pt' => 2.60267555046588E-02,
-                'qt' => 1.56250000000000E-02,
-                'gal' => 3.90625000000000E-03,
-                'l' => 1.47899822520213E-02,
-                'lt' => 1.47899822520213E-02,
-            ],
-            'oz' => [
-                'tsp' => 6.00000000000000E+00,
-                'tbs' => 2.00000000000000E+00,
-                'oz' => 1.0,
-                'cup' => 1.25000000000000E-01,
-                'pt' => 6.25000000000000E-02,
-                'us_pt' => 6.25000000000000E-02,
-                'uk_pt' => 5.20535110093176E-02,
-                'qt' => 3.12500000000000E-02,
-                'gal' => 7.81250000000000E-03,
-                'l' => 2.95799645040426E-02,
-                'lt' => 2.95799645040426E-02,
-            ],
-            'cup' => [
-                'tsp' => 4.80000000000000E+01,
-                'tbs' => 1.60000000000000E+01,
-                'oz' => 8.00000000000000E+00,
-                'cup' => 1.0,
-                'pt' => 5.00000000000000E-01,
-                'us_pt' => 5.00000000000000E-01,
-                'uk_pt' => 4.16428088074541E-01,
-                'qt' => 2.50000000000000E-01,
-                'gal' => 6.25000000000000E-02,
-                'l' => 2.36639716032341E-01,
-                'lt' => 2.36639716032341E-01,
-            ],
-            'pt' => [
-                'tsp' => 9.60000000000000E+01,
-                'tbs' => 3.20000000000000E+01,
-                'oz' => 1.60000000000000E+01,
-                'cup' => 2.00000000000000E+00,
-                'pt' => 1.0,
-                'us_pt' => 1.0,
-                'uk_pt' => 8.32856176149081E-01,
-                'qt' => 5.00000000000000E-01,
-                'gal' => 1.25000000000000E-01,
-                'l' => 4.73279432064682E-01,
-                'lt' => 4.73279432064682E-01,
-            ],
-            'us_pt' => [
-                'tsp' => 9.60000000000000E+01,
-                'tbs' => 3.20000000000000E+01,
-                'oz' => 1.60000000000000E+01,
-                'cup' => 2.00000000000000E+00,
-                'pt' => 1.0,
-                'us_pt' => 1.0,
-                'uk_pt' => 8.32856176149081E-01,
-                'qt' => 5.00000000000000E-01,
-                'gal' => 1.25000000000000E-01,
-                'l' => 4.73279432064682E-01,
-                'lt' => 4.73279432064682E-01,
-            ],
-            'uk_pt' => [
-                'tsp' => 1.15266000000000E+02,
-                'tbs' => 3.84220000000000E+01,
-                'oz' => 1.92110000000000E+01,
-                'cup' => 2.40137500000000E+00,
-                'pt' => 1.20068750000000E+00,
-                'us_pt' => 1.20068750000000E+00,
-                'uk_pt' => 1.0,
-                'qt' => 6.00343750000000E-01,
-                'gal' => 1.50085937500000E-01,
-                'l' => 5.68260698087162E-01,
-                'lt' => 5.68260698087162E-01,
-            ],
-            'qt' => [
-                'tsp' => 1.92000000000000E+02,
-                'tbs' => 6.40000000000000E+01,
-                'oz' => 3.20000000000000E+01,
-                'cup' => 4.00000000000000E+00,
-                'pt' => 2.00000000000000E+00,
-                'us_pt' => 2.00000000000000E+00,
-                'uk_pt' => 1.66571235229816E+00,
-                'qt' => 1.0,
-                'gal' => 2.50000000000000E-01,
-                'l' => 9.46558864129363E-01,
-                'lt' => 9.46558864129363E-01,
-            ],
-            'gal' => [
-                'tsp' => 7.68000000000000E+02,
-                'tbs' => 2.56000000000000E+02,
-                'oz' => 1.28000000000000E+02,
-                'cup' => 1.60000000000000E+01,
-                'pt' => 8.00000000000000E+00,
-                'us_pt' => 8.00000000000000E+00,
-                'uk_pt' => 6.66284940919265E+00,
-                'qt' => 4.00000000000000E+00,
-                'gal' => 1.0,
-                'l' => 3.78623545651745E+00,
-                'lt' => 3.78623545651745E+00,
-            ],
-            'l' => [
-                'tsp' => 2.02840000000000E+02,
-                'tbs' => 6.76133333333333E+01,
-                'oz' => 3.38066666666667E+01,
-                'cup' => 4.22583333333333E+00,
-                'pt' => 2.11291666666667E+00,
-                'us_pt' => 2.11291666666667E+00,
-                'uk_pt' => 1.75975569552166E+00,
-                'qt' => 1.05645833333333E+00,
-                'gal' => 2.64114583333333E-01,
-                'l' => 1.0,
-                'lt' => 1.0,
-            ],
-            'lt' => [
-                'tsp' => 2.02840000000000E+02,
-                'tbs' => 6.76133333333333E+01,
-                'oz' => 3.38066666666667E+01,
-                'cup' => 4.22583333333333E+00,
-                'pt' => 2.11291666666667E+00,
-                'us_pt' => 2.11291666666667E+00,
-                'uk_pt' => 1.75975569552166E+00,
-                'qt' => 1.05645833333333E+00,
-                'gal' => 2.64114583333333E-01,
-                'l' => 1.0,
-                'lt' => 1.0,
-            ],
-        ],
-    ];
-
     /**
      * parseComplex.
      *
@@ -2585,69 +1882,68 @@ public static function ERFC($x)
      *    getConversionGroups
      * Returns a list of the different conversion groups for UOM conversions.
      *
+     * @Deprecated Use the getConversionCategories() method in the ConvertUOM class instead
+     *
      * @return array
      */
     public static function getConversionGroups()
     {
-        $conversionGroups = [];
-        foreach (self::$conversionUnits as $conversionUnit) {
-            $conversionGroups[] = $conversionUnit['Group'];
-        }
-
-        return array_merge(array_unique($conversionGroups));
+        return Engineering\ConvertUOM::getConversionCategories();
     }
 
     /**
      *    getConversionGroupUnits
      * Returns an array of units of measure, for a specified conversion group, or for all groups.
      *
-     * @param string $group The group whose units of measure you want to retrieve
+     * @Deprecated Use the getConversionCategoryUnits() method in the ConvertUOM class instead
+     *
+     * @param null|mixed $category
      *
      * @return array
      */
-    public static function getConversionGroupUnits($group = null)
+    public static function getConversionGroupUnits($category = null)
     {
-        $conversionGroups = [];
-        foreach (self::$conversionUnits as $conversionUnit => $conversionGroup) {
-            if (($group === null) || ($conversionGroup['Group'] == $group)) {
-                $conversionGroups[$conversionGroup['Group']][] = $conversionUnit;
-            }
-        }
-
-        return $conversionGroups;
+        return Engineering\ConvertUOM::getConversionCategoryUnits($category);
     }
 
     /**
      * getConversionGroupUnitDetails.
      *
-     * @param string $group The group whose units of measure you want to retrieve
+     * @Deprecated Use the getConversionCategoryUnitDetails() method in the ConvertUOM class instead
+     *
+     * @param null|mixed $category
      *
      * @return array
      */
-    public static function getConversionGroupUnitDetails($group = null)
-    {
-        $conversionGroups = [];
-        foreach (self::$conversionUnits as $conversionUnit => $conversionGroup) {
-            if (($group === null) || ($conversionGroup['Group'] == $group)) {
-                $conversionGroups[$conversionGroup['Group']][] = [
-                    'unit' => $conversionUnit,
-                    'description' => $conversionGroup['Unit Name'],
-                ];
-            }
-        }
-
-        return $conversionGroups;
+    public static function getConversionGroupUnitDetails($category = null)
+    {
+        return Engineering\ConvertUOM::getConversionCategoryUnitDetails($category);
     }
 
     /**
      *    getConversionMultipliers
      * Returns an array of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM().
      *
+     * @Deprecated Use the getConversionMultipliers() method in the ConvertUOM class instead
+     *
      * @return array of mixed
      */
     public static function getConversionMultipliers()
     {
-        return self::$conversionMultipliers;
+        return Engineering\ConvertUOM::getConversionMultipliers();
+    }
+
+    /**
+     *    getBinaryConversionMultipliers
+     * Returns an array of the additional Multiplier prefixes that can be used with Information Units of Measure in CONVERTUOM().
+     *
+     * @Deprecated Use the getBinaryConversionMultipliers() method in the ConvertUOM class instead
+     *
+     * @return array of mixed
+     */
+    public static function getBinaryConversionMultipliers()
+    {
+        return Engineering\ConvertUOM::getBinaryConversionMultipliers();
     }
 
     /**
@@ -2660,7 +1956,9 @@ public static function getConversionMultipliers()
      *    Excel Function:
      *        CONVERT(value,fromUOM,toUOM)
      *
-     * @param float $value the value in fromUOM to convert
+     * @Deprecated Use the CONVERT() method in the ConvertUOM class instead
+     *
+     * @param float|int $value the value in fromUOM to convert
      * @param string $fromUOM the units for value
      * @param string $toUOM the units for the result
      *
@@ -2668,93 +1966,6 @@ public static function getConversionMultipliers()
      */
     public static function CONVERTUOM($value, $fromUOM, $toUOM)
     {
-        $value = Functions::flattenSingleValue($value);
-        $fromUOM = Functions::flattenSingleValue($fromUOM);
-        $toUOM = Functions::flattenSingleValue($toUOM);
-
-        if (!is_numeric($value)) {
-            return Functions::VALUE();
-        }
-        $fromMultiplier = 1.0;
-        if (isset(self::$conversionUnits[$fromUOM])) {
-            $unitGroup1 = self::$conversionUnits[$fromUOM]['Group'];
-        } else {
-            $fromMultiplier = substr($fromUOM, 0, 1);
-            $fromUOM = substr($fromUOM, 1);
-            if (isset(self::$conversionMultipliers[$fromMultiplier])) {
-                $fromMultiplier = self::$conversionMultipliers[$fromMultiplier]['multiplier'];
-            } else {
-                return Functions::NA();
-            }
-            if ((isset(self::$conversionUnits[$fromUOM])) && (self::$conversionUnits[$fromUOM]['AllowPrefix'])) {
-                $unitGroup1 = self::$conversionUnits[$fromUOM]['Group'];
-            } else {
-                return Functions::NA();
-            }
-        }
-        $value *= $fromMultiplier;
-
-        $toMultiplier = 1.0;
-        if (isset(self::$conversionUnits[$toUOM])) {
-            $unitGroup2 = self::$conversionUnits[$toUOM]['Group'];
-        } else {
-            $toMultiplier = substr($toUOM, 0, 1);
-            $toUOM = substr($toUOM, 1);
-            if (isset(self::$conversionMultipliers[$toMultiplier])) {
-                $toMultiplier = self::$conversionMultipliers[$toMultiplier]['multiplier'];
-            } else {
-                return Functions::NA();
-            }
-            if ((isset(self::$conversionUnits[$toUOM])) && (self::$conversionUnits[$toUOM]['AllowPrefix'])) {
-                $unitGroup2 = self::$conversionUnits[$toUOM]['Group'];
-            } else {
-                return Functions::NA();
-            }
-        }
-        if ($unitGroup1 != $unitGroup2) {
-            return Functions::NA();
-        }
-
-        if (($fromUOM == $toUOM) && ($fromMultiplier == $toMultiplier)) {
-            //    We've already factored $fromMultiplier into the value, so we need
-            //        to reverse it again
-            return $value / $fromMultiplier;
-        } elseif ($unitGroup1 == 'Temperature') {
-            if (($fromUOM == 'F') || ($fromUOM == 'fah')) {
-                if (($toUOM == 'F') || ($toUOM == 'fah')) {
-                    return $value;
-                }
-                $value = (($value - 32) / 1.8);
-                if (($toUOM == 'K') || ($toUOM == 'kel')) {
-                    $value += 273.15;
-                }
-
-                return $value;
-            } elseif (
-                (($fromUOM == 'K') || ($fromUOM == 'kel')) &&
-                (($toUOM == 'K') || ($toUOM == 'kel'))
-            ) {
-                return $value;
-            } elseif (
-                (($fromUOM == 'C') || ($fromUOM == 'cel')) &&
-                (($toUOM == 'C') || ($toUOM == 'cel'))
-            ) {
-                return $value;
-            }
-            if (($toUOM == 'F') || ($toUOM == 'fah')) {
-                if (($fromUOM == 'K') || ($fromUOM == 'kel')) {
-                    $value -= 273.15;
-                }
-
-                return ($value * 1.8) + 32;
-            }
-            if (($toUOM == 'C') || ($toUOM == 'cel')) {
-                return $value - 273.15;
-            }
-
-            return $value + 273.15;
-        }
-
-        return ($value * self::$unitConversions[$unitGroup1][$fromUOM][$toUOM]) / $toMultiplier;
+        return Engineering\ConvertUOM::CONVERT($value, $fromUOM, $toUOM);
     }
 }
diff --git a/src/PhpSpreadsheet/Calculation/Engineering/ConvertUOM.php b/src/PhpSpreadsheet/Calculation/Engineering/ConvertUOM.php
new file mode 100644
index 0000000000..0aafe05ec3
--- /dev/null
+++ b/src/PhpSpreadsheet/Calculation/Engineering/ConvertUOM.php
@@ -0,0 +1,684 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheet\Calculation\Engineering;
+
+use PhpOffice\PhpSpreadsheet\Calculation\Exception;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+
+class ConvertUOM
+{
+    public const CATEGORY_WEIGHT_AND_MASS = 'Weight and Mass';
+    public const CATEGORY_DISTANCE = 'Distance';
+    public const CATEGORY_TIME = 'Time';
+    public const CATEGORY_PRESSURE = 'Pressure';
+    public const CATEGORY_FORCE = 'Force';
+    public const CATEGORY_ENERGY = 'Energy';
+    public const CATEGORY_POWER = 'Power';
+    public const CATEGORY_MAGNETISM = 'Magnetism';
+    public const CATEGORY_TEMPERATURE = 'Temperature';
+    public const CATEGORY_VOLUME = 'Volume and Liquid Measure';
+    public const CATEGORY_AREA = 'Area';
+    public const CATEGORY_INFORMATION = 'Information';
+    public const CATEGORY_SPEED = 'Speed';
+
+    /**
+     * Details of the Units of measure that can be used in CONVERTUOM().
+     *
+     * @var mixed[]
+     */
+    private static $conversionUnits = [
+        // Weight and Mass
+        'g' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Gram', 'AllowPrefix' => true],
+        'sg' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Slug', 'AllowPrefix' => false],
+        'lbm' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Pound mass (avoirdupois)', 'AllowPrefix' => false],
+        'u' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'U (atomic mass unit)', 'AllowPrefix' => true],
+        'ozm' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Ounce mass (avoirdupois)', 'AllowPrefix' => false],
+        'grain' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Grain', 'AllowPrefix' => false],
+        'cwt' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'U.S. (short) hundredweight', 'AllowPrefix' => false],
+        'shweight' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'U.S. (short) hundredweight', 'AllowPrefix' => false],
+        'uk_cwt' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Imperial hundredweight', 'AllowPrefix' => false],
+        'lcwt' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Imperial hundredweight', 'AllowPrefix' => false],
+        'hweight' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Imperial hundredweight', 'AllowPrefix' => false],
+        'stone' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Stone', 'AllowPrefix' => false],
+        'ton' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Ton', 'AllowPrefix' => false],
+        'uk_ton' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Imperial ton', 'AllowPrefix' => false],
+        'LTON' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Imperial ton', 'AllowPrefix' => false],
+        'brton' => ['Group' => self::CATEGORY_WEIGHT_AND_MASS, 'Unit Name' => 'Imperial ton', 'AllowPrefix' => false],
+        // Distance
+        'm' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Meter', 'AllowPrefix' => true],
+        'mi' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Statute mile', 'AllowPrefix' => false],
+        'Nmi' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Nautical mile', 'AllowPrefix' => false],
+        'in' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Inch', 'AllowPrefix' => false],
+        'ft' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Foot', 'AllowPrefix' => false],
+        'yd' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Yard', 'AllowPrefix' => false],
+        'ang' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Angstrom', 'AllowPrefix' => true],
+        'ell' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Ell', 'AllowPrefix' => false],
+        'ly' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Light Year', 'AllowPrefix' => false],
+        'parsec' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Parsec', 'AllowPrefix' => false],
+        'pc' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Parsec', 'AllowPrefix' => false],
+        'Pica' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Pica (1/72 in)', 'AllowPrefix' => false],
+        'Picapt' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Pica (1/72 in)', 'AllowPrefix' => false],
+        'pica' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'Pica (1/6 in)', 'AllowPrefix' => false],
+        'survey_mi' => ['Group' => self::CATEGORY_DISTANCE, 'Unit Name' => 'U.S survey mile (statute mile)', 'AllowPrefix' => false],
+        // Time
+        'yr' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Year', 'AllowPrefix' => false],
+        'day' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Day', 'AllowPrefix' => false],
+        'd' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Day', 'AllowPrefix' => false],
+        'hr' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Hour', 'AllowPrefix' => false],
+        'mn' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Minute', 'AllowPrefix' => false],
+        'min' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Minute', 'AllowPrefix' => false],
+        'sec' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Second', 'AllowPrefix' => true],
+        's' => ['Group' => self::CATEGORY_TIME, 'Unit Name' => 'Second', 'AllowPrefix' => true],
+        // Pressure
+        'Pa' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'Pascal', 'AllowPrefix' => true],
+        'p' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'Pascal', 'AllowPrefix' => true],
+        'atm' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'Atmosphere', 'AllowPrefix' => true],
+        'at' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'Atmosphere', 'AllowPrefix' => true],
+        'mmHg' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'mm of Mercury', 'AllowPrefix' => true],
+        'psi' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'PSI', 'AllowPrefix' => true],
+        'Torr' => ['Group' => self::CATEGORY_PRESSURE, 'Unit Name' => 'Torr', 'AllowPrefix' => true],
+        // Force
+        'N' => ['Group' => self::CATEGORY_FORCE, 'Unit Name' => 'Newton', 'AllowPrefix' => true],
+        'dyn' => ['Group' => self::CATEGORY_FORCE, 'Unit Name' => 'Dyne', 'AllowPrefix' => true],
+        'dy' => ['Group' => self::CATEGORY_FORCE, 'Unit Name' => 'Dyne', 'AllowPrefix' => true],
+        'lbf' => ['Group' => self::CATEGORY_FORCE, 'Unit Name' => 'Pound force', 'AllowPrefix' => false],
+        'pond' => ['Group' => self::CATEGORY_FORCE, 'Unit Name' => 'Pond', 'AllowPrefix' => true],
+        // Energy
+        'J' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Joule', 'AllowPrefix' => true],
+        'e' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Erg', 'AllowPrefix' => true],
+        'c' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Thermodynamic calorie', 'AllowPrefix' => true],
+        'cal' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'IT calorie', 'AllowPrefix' => true],
+        'eV' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Electron volt', 'AllowPrefix' => true],
+        'ev' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Electron volt', 'AllowPrefix' => true],
+        'HPh' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Horsepower-hour', 'AllowPrefix' => false],
+        'hh' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Horsepower-hour', 'AllowPrefix' => false],
+        'Wh' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Watt-hour', 'AllowPrefix' => true],
+        'wh' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Watt-hour', 'AllowPrefix' => true],
+        'flb' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'Foot-pound', 'AllowPrefix' => false],
+        'BTU' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'BTU', 'AllowPrefix' => false],
+        'btu' => ['Group' => self::CATEGORY_ENERGY, 'Unit Name' => 'BTU', 'AllowPrefix' => false],
+        // Power
+        'HP' => ['Group' => self::CATEGORY_POWER, 'Unit Name' => 'Horsepower', 'AllowPrefix' => false],
+        'h' => ['Group' => self::CATEGORY_POWER, 'Unit Name' => 'Horsepower', 'AllowPrefix' => false],
+        'W' => ['Group' => self::CATEGORY_POWER, 'Unit Name' => 'Watt', 'AllowPrefix' => true],
+        'w' => ['Group' => self::CATEGORY_POWER, 'Unit Name' => 'Watt', 'AllowPrefix' => true],
+        'PS' => ['Group' => self::CATEGORY_POWER, 'Unit Name' => 'Pferdestärke', 'AllowPrefix' => false],
+        'T' => ['Group' => self::CATEGORY_MAGNETISM, 'Unit Name' => 'Tesla', 'AllowPrefix' => true],
+        'ga' => ['Group' => self::CATEGORY_MAGNETISM, 'Unit Name' => 'Gauss', 'AllowPrefix' => true],
+        // Temperature
+        'C' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Degrees Celsius', 'AllowPrefix' => false],
+        'cel' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Degrees Celsius', 'AllowPrefix' => false],
+        'F' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Degrees Fahrenheit', 'AllowPrefix' => false],
+        'fah' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Degrees Fahrenheit', 'AllowPrefix' => false],
+        'K' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Kelvin', 'AllowPrefix' => false],
+        'kel' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Kelvin', 'AllowPrefix' => false],
+        'Rank' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Degrees Rankine', 'AllowPrefix' => false],
+        'Reau' => ['Group' => self::CATEGORY_TEMPERATURE, 'Unit Name' => 'Degrees Réaumur', 'AllowPrefix' => false],
+        // Volume
+        'l' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Litre', 'AllowPrefix' => true],
+        'L' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Litre', 'AllowPrefix' => true],
+        'lt' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Litre', 'AllowPrefix' => true],
+        'tsp' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Teaspoon', 'AllowPrefix' => false],
+        'tspm' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Modern Teaspoon', 'AllowPrefix' => false],
+        'tbs' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Tablespoon', 'AllowPrefix' => false],
+        'oz' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Fluid Ounce', 'AllowPrefix' => false],
+        'cup' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cup', 'AllowPrefix' => false],
+        'pt' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'U.S. Pint', 'AllowPrefix' => false],
+        'us_pt' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'U.S. Pint', 'AllowPrefix' => false],
+        'uk_pt' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'U.K. Pint', 'AllowPrefix' => false],
+        'qt' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Quart', 'AllowPrefix' => false],
+        'uk_qt' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Imperial Quart (UK)', 'AllowPrefix' => false],
+        'gal' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Gallon', 'AllowPrefix' => false],
+        'uk_gal' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Imperial Gallon (UK)', 'AllowPrefix' => false],
+        'ang3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Angstrom', 'AllowPrefix' => true],
+        'ang^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Angstrom', 'AllowPrefix' => true],
+        'barrel' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'US Oil Barrel', 'AllowPrefix' => false],
+        'bushel' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'US Bushel', 'AllowPrefix' => false],
+        'in3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Inch', 'AllowPrefix' => false],
+        'in^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Inch', 'AllowPrefix' => false],
+        'ft3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Foot', 'AllowPrefix' => false],
+        'ft^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Foot', 'AllowPrefix' => false],
+        'ly3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Light Year', 'AllowPrefix' => false],
+        'ly^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Light Year', 'AllowPrefix' => false],
+        'm3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Meter', 'AllowPrefix' => true],
+        'm^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Meter', 'AllowPrefix' => true],
+        'mi3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Mile', 'AllowPrefix' => false],
+        'mi^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Mile', 'AllowPrefix' => false],
+        'yd3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Yard', 'AllowPrefix' => false],
+        'yd^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Yard', 'AllowPrefix' => false],
+        'Nmi3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Nautical Mile', 'AllowPrefix' => false],
+        'Nmi^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Nautical Mile', 'AllowPrefix' => false],
+        'Pica3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Pica', 'AllowPrefix' => false],
+        'Pica^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Pica', 'AllowPrefix' => false],
+        'Picapt3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Pica', 'AllowPrefix' => false],
+        'Picapt^3' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Cubic Pica', 'AllowPrefix' => false],
+        'GRT' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Gross Registered Ton', 'AllowPrefix' => false],
+        'regton' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Gross Registered Ton', 'AllowPrefix' => false],
+        'MTON' => ['Group' => self::CATEGORY_VOLUME, 'Unit Name' => 'Measurement Ton (Freight Ton)', 'AllowPrefix' => false],
+        // Area
+        'ha' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Hectare', 'AllowPrefix' => true],
+        'uk_acre' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'International Acre', 'AllowPrefix' => false],
+        'us_acre' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'US Survey/Statute Acre', 'AllowPrefix' => false],
+        'ang2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Angstrom', 'AllowPrefix' => true],
+        'ang^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Angstrom', 'AllowPrefix' => true],
+        'ar' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Are', 'AllowPrefix' => true],
+        'ft2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Feet', 'AllowPrefix' => false],
+        'ft^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Feet', 'AllowPrefix' => false],
+        'in2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Inches', 'AllowPrefix' => false],
+        'in^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Inches', 'AllowPrefix' => false],
+        'ly2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Light Years', 'AllowPrefix' => false],
+        'ly^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Light Years', 'AllowPrefix' => false],
+        'm2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Meters', 'AllowPrefix' => true],
+        'm^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Meters', 'AllowPrefix' => true],
+        'Morgen' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Morgen', 'AllowPrefix' => false],
+        'mi2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Miles', 'AllowPrefix' => false],
+        'mi^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Miles', 'AllowPrefix' => false],
+        'Nmi2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Nautical Miles', 'AllowPrefix' => false],
+        'Nmi^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Nautical Miles', 'AllowPrefix' => false],
+        'Pica2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Pica', 'AllowPrefix' => false],
+        'Pica^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Pica', 'AllowPrefix' => false],
+        'Picapt2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Pica', 'AllowPrefix' => false],
+        'Picapt^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Pica', 'AllowPrefix' => false],
+        'yd2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Yards', 'AllowPrefix' => false],
+        'yd^2' => ['Group' => self::CATEGORY_AREA, 'Unit Name' => 'Square Yards', 'AllowPrefix' => false],
+        // Information
+        'byte' => ['Group' => self::CATEGORY_INFORMATION, 'Unit Name' => 'Byte', 'AllowPrefix' => true],
+        'bit' => ['Group' => self::CATEGORY_INFORMATION, 'Unit Name' => 'Bit', 'AllowPrefix' => true],
+        // Speed
+        'm/s' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Meters per second', 'AllowPrefix' => true],
+        'm/sec' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Meters per second', 'AllowPrefix' => true],
+        'm/h' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Meters per hour', 'AllowPrefix' => true],
+        'm/hr' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Meters per hour', 'AllowPrefix' => true],
+        'mph' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Miles per hour', 'AllowPrefix' => false],
+        'admkn' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Admiralty Knot', 'AllowPrefix' => false],
+        'kn' => ['Group' => self::CATEGORY_SPEED, 'Unit Name' => 'Knot', 'AllowPrefix' => false],
+    ];
+
+    /**
+     * Details of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM().
+     *
+     * @var mixed[]
+     */
+    private static $conversionMultipliers = [
+        'Y' => ['multiplier' => 1E24, 'name' => 'yotta'],
+        'Z' => ['multiplier' => 1E21, 'name' => 'zetta'],
+        'E' => ['multiplier' => 1E18, 'name' => 'exa'],
+        'P' => ['multiplier' => 1E15, 'name' => 'peta'],
+        'T' => ['multiplier' => 1E12, 'name' => 'tera'],
+        'G' => ['multiplier' => 1E9, 'name' => 'giga'],
+        'M' => ['multiplier' => 1E6, 'name' => 'mega'],
+        'k' => ['multiplier' => 1E3, 'name' => 'kilo'],
+        'h' => ['multiplier' => 1E2, 'name' => 'hecto'],
+        'e' => ['multiplier' => 1E1, 'name' => 'dekao'],
+        'da' => ['multiplier' => 1E1, 'name' => 'dekao'],
+        'd' => ['multiplier' => 1E-1, 'name' => 'deci'],
+        'c' => ['multiplier' => 1E-2, 'name' => 'centi'],
+        'm' => ['multiplier' => 1E-3, 'name' => 'milli'],
+        'u' => ['multiplier' => 1E-6, 'name' => 'micro'],
+        'n' => ['multiplier' => 1E-9, 'name' => 'nano'],
+        'p' => ['multiplier' => 1E-12, 'name' => 'pico'],
+        'f' => ['multiplier' => 1E-15, 'name' => 'femto'],
+        'a' => ['multiplier' => 1E-18, 'name' => 'atto'],
+        'z' => ['multiplier' => 1E-21, 'name' => 'zepto'],
+        'y' => ['multiplier' => 1E-24, 'name' => 'yocto'],
+    ];
+
+    /**
+     * Details of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM().
+     *
+     * @var mixed[]
+     */
+    private static $binaryConversionMultipliers = [
+        'Yi' => ['multiplier' => 2 ** 80, 'name' => 'yobi'],
+        'Zi' => ['multiplier' => 2 ** 70, 'name' => 'zebi'],
+        'Ei' => ['multiplier' => 2 ** 60, 'name' => 'exbi'],
+        'Pi' => ['multiplier' => 2 ** 50, 'name' => 'pebi'],
+        'Ti' => ['multiplier' => 2 ** 40, 'name' => 'tebi'],
+        'Gi' => ['multiplier' => 2 ** 30, 'name' => 'gibi'],
+        'Mi' => ['multiplier' => 2 ** 20, 'name' => 'mebi'],
+        'ki' => ['multiplier' => 2 ** 10, 'name' => 'kibi'],
+    ];
+
+    /**
+     * Details of the Units of measure conversion factors, organised by group.
+     *
+     * @var mixed[]
+     */
+    private static $unitConversions = [
+        // Conversion uses gram (g) as an intermediate unit
+        self::CATEGORY_WEIGHT_AND_MASS => [
+            'g' => 1.0,
+            'sg' => 6.85217658567918E-05,
+            'lbm' => 2.20462262184878E-03,
+            'u' => 6.02214179421676E+23,
+            'ozm' => 3.52739619495804E-02,
+            'grain' => 1.54323583529414E+01,
+            'cwt' => 2.20462262184878E-05,
+            'shweight' => 2.20462262184878E-05,
+            'uk_cwt' => 1.96841305522212E-05,
+            'lcwt' => 1.96841305522212E-05,
+            'hweight' => 1.96841305522212E-05,
+            'stone' => 1.57473044417770E-04,
+            'ton' => 1.10231131092439E-06,
+            'uk_ton' => 9.84206527611061E-07,
+            'LTON' => 9.84206527611061E-07,
+            'brton' => 9.84206527611061E-07,
+        ],
+        // Conversion uses meter (m) as an intermediate unit
+        self::CATEGORY_DISTANCE => [
+            'm' => 1.0,
+            'mi' => 6.21371192237334E-04,
+            'Nmi' => 5.39956803455724E-04,
+            'in' => 3.93700787401575E+01,
+            'ft' => 3.28083989501312E+00,
+            'yd' => 1.09361329833771E+00,
+            'ang' => 1.0E+10,
+            'ell' => 8.74890638670166E-01,
+            'ly' => 1.05700083402462E-16,
+            'parsec' => 3.24077928966473E-17,
+            'pc' => 3.24077928966473E-17,
+            'Pica' => 2.83464566929134E+03,
+            'Picapt' => 2.83464566929134E+03,
+            'pica' => 2.36220472440945E+02,
+            'survey_mi' => 6.21369949494950E-04,
+        ],
+        // Conversion uses second (s) as an intermediate unit
+        self::CATEGORY_TIME => [
+            'yr' => 3.16880878140289E-08,
+            'day' => 1.15740740740741E-05,
+            'd' => 1.15740740740741E-05,
+            'hr' => 2.77777777777778E-04,
+            'mn' => 1.66666666666667E-02,
+            'min' => 1.66666666666667E-02,
+            'sec' => 1.0,
+            's' => 1.0,
+        ],
+        // Conversion uses Pascal (Pa) as an intermediate unit
+        self::CATEGORY_PRESSURE => [
+            'Pa' => 1.0,
+            'p' => 1.0,
+            'atm' => 9.86923266716013E-06,
+            'at' => 9.86923266716013E-06,
+            'mmHg' => 7.50063755419211E-03,
+            'psi' => 1.45037737730209E-04,
+            'Torr' => 7.50061682704170E-03,
+        ],
+        // Conversion uses Newton (N) as an intermediate unit
+        self::CATEGORY_FORCE => [
+            'N' => 1.0,
+            'dyn' => 1.0E+5,
+            'dy' => 1.0E+5,
+            'lbf' => 2.24808923655339E-01,
+            'pond' => 1.01971621297793E+02,
+        ],
+        // Conversion uses Joule (J) as an intermediate unit
+        self::CATEGORY_ENERGY => [
+            'J' => 1.0,
+            'e' => 9.99999519343231E+06,
+            'c' => 2.39006249473467E-01,
+            'cal' => 2.38846190642017E-01,
+            'eV' => 6.24145700000000E+18,
+            'ev' => 6.24145700000000E+18,
+            'HPh' => 3.72506430801000E-07,
+            'hh' => 3.72506430801000E-07,
+            'Wh' => 2.77777916238711E-04,
+            'wh' => 2.77777916238711E-04,
+            'flb' => 2.37304222192651E+01,
+            'BTU' => 9.47815067349015E-04,
+            'btu' => 9.47815067349015E-04,
+        ],
+        // Conversion uses Horsepower (HP) as an intermediate unit
+        self::CATEGORY_POWER => [
+            'HP' => 1.0,
+            'h' => 1.0,
+            'W' => 7.45699871582270E+02,
+            'w' => 7.45699871582270E+02,
+            'PS' => 1.01386966542400E+00,
+        ],
+        // Conversion uses Tesla (T) as an intermediate unit
+        self::CATEGORY_MAGNETISM => [
+            'T' => 1.0,
+            'ga' => 10000.0,
+        ],
+        // Conversion uses litre (l) as an intermediate unit
+        self::CATEGORY_VOLUME => [
+            'l' => 1.0,
+            'L' => 1.0,
+            'lt' => 1.0,
+            'tsp' => 2.02884136211058E+02,
+            'tspm' => 2.0E+02,
+            'tbs' => 6.76280454036860E+01,
+            'oz' => 3.38140227018430E+01,
+            'cup' => 4.22675283773038E+00,
+            'pt' => 2.11337641886519E+00,
+            'us_pt' => 2.11337641886519E+00,
+            'uk_pt' => 1.75975398639270E+00,
+            'qt' => 1.05668820943259E+00,
+            'uk_qt' => 8.79876993196351E-01,
+            'gal' => 2.64172052358148E-01,
+            'uk_gal' => 2.19969248299088E-01,
+            'ang3' => 1.0E+27,
+            'ang^3' => 1.0E+27,
+            'barrel' => 6.28981077043211E-03,
+            'bushel' => 2.83775932584017E-02,
+            'in3' => 6.10237440947323E+01,
+            'in^3' => 6.10237440947323E+01,
+            'ft3' => 3.53146667214886E-02,
+            'ft^3' => 3.53146667214886E-02,
+            'ly3' => 1.18093498844171E-51,
+            'ly^3' => 1.18093498844171E-51,
+            'm3' => 1.0E-03,
+            'm^3' => 1.0E-03,
+            'mi3' => 2.39912758578928E-13,
+            'mi^3' => 2.39912758578928E-13,
+            'yd3' => 1.30795061931439E-03,
+            'yd^3' => 1.30795061931439E-03,
+            'Nmi3' => 1.57426214685811E-13,
+            'Nmi^3' => 1.57426214685811E-13,
+            'Pica3' => 2.27769904358706E+07,
+            'Pica^3' => 2.27769904358706E+07,
+            'Picapt3' => 2.27769904358706E+07,
+            'Picapt^3' => 2.27769904358706E+07,
+            'GRT' => 3.53146667214886E-04,
+            'regton' => 3.53146667214886E-04,
+            'MTON' => 8.82866668037215E-04,
+        ],
+        // Conversion uses hectare (ha) as an intermediate unit
+        self::CATEGORY_AREA => [
+            'ha' => 1.0,
+            'uk_acre' => 2.47105381467165E+00,
+            'us_acre' => 2.47104393046628E+00,
+            'ang2' => 1.0E+24,
+            'ang^2' => 1.0E+24,
+            'ar' => 1.0E+02,
+            'ft2' => 1.07639104167097E+05,
+            'ft^2' => 1.07639104167097E+05,
+            'in2' => 1.55000310000620E+07,
+            'in^2' => 1.55000310000620E+07,
+            'ly2' => 1.11725076312873E-28,
+            'ly^2' => 1.11725076312873E-28,
+            'm2' => 1.0E+04,
+            'm^2' => 1.0E+04,
+            'Morgen' => 4.0E+00,
+            'mi2' => 3.86102158542446E-03,
+            'mi^2' => 3.86102158542446E-03,
+            'Nmi2' => 2.91553349598123E-03,
+            'Nmi^2' => 2.91553349598123E-03,
+            'Pica2' => 8.03521607043214E+10,
+            'Pica^2' => 8.03521607043214E+10,
+            'Picapt2' => 8.03521607043214E+10,
+            'Picapt^2' => 8.03521607043214E+10,
+            'yd2' => 1.19599004630108E+04,
+            'yd^2' => 1.19599004630108E+04,
+        ],
+        // Conversion uses bit (bit) as an intermediate unit
+        self::CATEGORY_INFORMATION => [
+            'bit' => 1.0,
+            'byte' => 0.125,
+        ],
+        // Conversion uses Meters per Second (m/s) as an intermediate unit
+        self::CATEGORY_SPEED => [
+            'm/s' => 1.0,
+            'm/sec' => 1.0,
+            'm/h' => 3.60E+03,
+            'm/hr' => 3.60E+03,
+            'mph' => 2.23693629205440E+00,
+            'admkn' => 1.94260256941567E+00,
+            'kn' => 1.94384449244060E+00,
+        ],
+    ];
+
+    /**
+     *    getConversionGroups
+     * Returns a list of the different conversion groups for UOM conversions.
+     *
+     * @return array
+     */
+    public static function getConversionCategories()
+    {
+        $conversionGroups = [];
+        foreach (self::$conversionUnits as $conversionUnit) {
+            $conversionGroups[] = $conversionUnit['Group'];
+        }
+
+        return array_merge(array_unique($conversionGroups));
+    }
+
+    /**
+     *    getConversionGroupUnits
+     * Returns an array of units of measure, for a specified conversion group, or for all groups.
+     *
+     * @param string $category The group whose units of measure you want to retrieve
+     *
+     * @return array
+     */
+    public static function getConversionCategoryUnits($category = null)
+    {
+        $conversionGroups = [];
+        foreach (self::$conversionUnits as $conversionUnit => $conversionGroup) {
+            if (($category === null) || ($conversionGroup['Group'] == $category)) {
+                $conversionGroups[$conversionGroup['Group']][] = $conversionUnit;
+            }
+        }
+
+        return $conversionGroups;
+    }
+
+    /**
+     * getConversionGroupUnitDetails.
+     *
+     * @param string $category The group whose units of measure you want to retrieve
+     *
+     * @return array
+     */
+    public static function getConversionCategoryUnitDetails($category = null)
+    {
+        $conversionGroups = [];
+        foreach (self::$conversionUnits as $conversionUnit => $conversionGroup) {
+            if (($category === null) || ($conversionGroup['Group'] == $category)) {
+                $conversionGroups[$conversionGroup['Group']][] = [
+                    'unit' => $conversionUnit,
+                    'description' => $conversionGroup['Unit Name'],
+                ];
+            }
+        }
+
+        return $conversionGroups;
+    }
+
+    /**
+     *    getConversionMultipliers
+     * Returns an array of the Multiplier prefixes that can be used with Units of Measure in CONVERTUOM().
+     *
+     * @return array of mixed
+     */
+    public static function getConversionMultipliers()
+    {
+        return self::$conversionMultipliers;
+    }
+
+    /**
+     *    getBinaryConversionMultipliers
+     * Returns an array of the additional Multiplier prefixes that can be used with Information Units of Measure in CONVERTUOM().
+     *
+     * @return array of mixed
+     */
+    public static function getBinaryConversionMultipliers()
+    {
+        return self::$binaryConversionMultipliers;
+    }
+
+    /**
+     * CONVERT.
+     *
+     * Converts a number from one measurement system to another.
+     *    For example, CONVERT can translate a table of distances in miles to a table of distances
+     * in kilometers.
+     *
+     *    Excel Function:
+     *        CONVERT(value,fromUOM,toUOM)
+     *
+     * @param float|int $value the value in fromUOM to convert
+     * @param string $fromUOM the units for value
+     * @param string $toUOM the units for the result
+     *
+     * @return float|string
+     */
+    public static function CONVERT($value, $fromUOM, $toUOM)
+    {
+        $value = Functions::flattenSingleValue($value);
+        $fromUOM = Functions::flattenSingleValue($fromUOM);
+        $toUOM = Functions::flattenSingleValue($toUOM);
+
+        if (!is_numeric($value)) {
+            return Functions::VALUE();
+        }
+
+        try {
+            [$fromUOM, $fromCategory, $fromMultiplier] = self::getUOMDetails($fromUOM);
+            [$toUOM, $toCategory, $toMultiplier] = self::getUOMDetails($toUOM);
+        } catch (Exception $e) {
+            return Functions::NA();
+        }
+
+        if ($fromCategory !== $toCategory) {
+            return Functions::NA();
+        }
+
+        $value *= $fromMultiplier;
+
+        if (($fromUOM === $toUOM) && ($fromMultiplier === $toMultiplier)) {
+            //    We've already factored $fromMultiplier into the value, so we need
+            //        to reverse it again
+            return $value / $fromMultiplier;
+        } elseif ($fromUOM === $toUOM) {
+            return $value / $toMultiplier;
+        } elseif ($fromCategory === self::CATEGORY_TEMPERATURE) {
+            return self::convertTemperature($fromUOM, $toUOM, $value);
+        }
+
+        $baseValue = $value * (1.0 / self::$unitConversions[$fromCategory][$fromUOM]);
+
+        return ($baseValue * self::$unitConversions[$fromCategory][$toUOM]) / $toMultiplier;
+    }
+
+    private static function getUOMDetails(string $uom)
+    {
+        if (isset(self::$conversionUnits[$uom])) {
+            $unitCategory = self::$conversionUnits[$uom]['Group'];
+
+            return [$uom, $unitCategory, 1.0];
+        }
+
+        // Check 1-character standard metric multiplier prefixes
+        $multiplierType = substr($uom, 0, 1);
+        $uom = substr($uom, 1);
+        if (isset(self::$conversionUnits[$uom], self::$conversionMultipliers[$multiplierType])) {
+            if (self::$conversionUnits[$uom]['AllowPrefix'] === false) {
+                throw new Exception('Prefix not allowed for UoM');
+            }
+            $unitCategory = self::$conversionUnits[$uom]['Group'];
+
+            return [$uom, $unitCategory, self::$conversionMultipliers[$multiplierType]['multiplier']];
+        }
+
+        $multiplierType .= substr($uom, 0, 1);
+        $uom = substr($uom, 1);
+
+        // Check 2-character standard metric multiplier prefixes
+        if (isset(self::$conversionUnits[$uom], self::$conversionMultipliers[$multiplierType])) {
+            if (self::$conversionUnits[$uom]['AllowPrefix'] === false) {
+                throw new Exception('Prefix not allowed for UoM');
+            }
+            $unitCategory = self::$conversionUnits[$uom]['Group'];
+
+            return [$uom, $unitCategory, self::$conversionMultipliers[$multiplierType]['multiplier']];
+        }
+
+        // Check 2-character binary multiplier prefixes
+        if (isset(self::$conversionUnits[$uom], self::$binaryConversionMultipliers[$multiplierType])) {
+            if (self::$conversionUnits[$uom]['AllowPrefix'] === false) {
+                throw new Exception('Prefix not allowed for UoM');
+            }
+            $unitCategory = self::$conversionUnits[$uom]['Group'];
+            if ($unitCategory !== 'Information') {
+                throw new Exception('Binary Prefix is only allowed for Information UoM');
+            }
+
+            return [$uom, $unitCategory, self::$binaryConversionMultipliers[$multiplierType]['multiplier']];
+        }
+
+        throw new Exception('UoM Not Found');
+    }
+
+    /**
+     * @param float|int $value
+     *
+     * @return float|int
+     */
+    protected static function convertTemperature(string $fromUOM, string $toUOM, $value)
+    {
+        $fromUOM = self::resolveTemperatureSynonyms($fromUOM);
+        $toUOM = self::resolveTemperatureSynonyms($toUOM);
+
+        if ($fromUOM === $toUOM) {
+            return $value;
+        }
+
+        // Convert to Kelvin
+        switch ($fromUOM) {
+            case 'F':
+                $value = ($value - 32) / 1.8 + 273.15;
+
+                break;
+            case 'C':
+                $value += 273.15;
+
+                break;
+            case 'Rank':
+                $value /= 1.8;
+
+                break;
+            case 'Reau':
+                $value = $value * 1.25 + 273.15;
+
+                break;
+        }
+
+        // Convert from Kelvin
+        switch ($toUOM) {
+            case 'F':
+                $value = ($value - 273.15) * 1.8 + 32.00;
+
+                break;
+            case 'C':
+                $value -= 273.15;
+
+                break;
+            case 'Rank':
+                $value *= 1.8;
+
+                break;
+            case 'Reau':
+                $value = ($value - 273.15) * 0.80000;
+
+                break;
+        }
+
+        return $value;
+    }
+
+    private static function resolveTemperatureSynonyms(string $uom)
+    {
+        switch ($uom) {
+            case 'fah':
+                return 'F';
+            case 'cel':
+                return 'C';
+            case 'kel':
+                return 'K';
+        }
+
+        return $uom;
+    }
+}
diff --git a/tests/data/Calculation/Engineering/CONVERTUOM.php b/tests/data/Calculation/Engineering/CONVERTUOM.php
index 248c2cd084..64aaef6244 100644
--- a/tests/data/Calculation/Engineering/CONVERTUOM.php
+++ b/tests/data/Calculation/Engineering/CONVERTUOM.php
@@ -1,18 +1,72 @@
 <?php
 
 return [
-    [
-        0.45359230974880999,
+    'Imperial from and to (mass)' => [
+        1.942559385723E-03,
         1.0,
-        'lbm',
+        'ozm',
+        'sg',
+    ],
+    'Same prefixed metric UoM' => [
+        5.0,
+        5.0,
+        'kg',
         'kg',
     ],
-    [
-        123.45,
-        123.45,
+    'Imperial to prefixed metric' => [
+        4.5359237E-01,
+        1.0,
+        'lbm',
         'kg',
+    ],
+    'Prefixed metric to prefixed metric, same unit' => [
+        0.2,
+        2.0,
+        'hg',
         'kg',
     ],
+    'Unprefixed metric to prefixed metric, same unit' => [
+        12.345000000000001,
+        12345,
+        'm',
+        'km',
+    ],
+    'Prefixed metric to unprefixed metric, same unit' => [
+        12345,
+        12.345000000000001,
+        'km',
+        'm',
+    ],
+    'Prefixed metric to imperial' => [
+        0.62137119223732995,
+        1,
+        'km',
+        'mi',
+    ],
+    'Prefixed metric to alternative metric' => [
+        1.23450000000000E+05,
+        12.345,
+        'um',
+        'ang',
+    ],
+    'Prefixed metric to alternative prefixed metric' => [
+        1.23450000000000E+02,
+        12.345,
+        'um',
+        'kang',
+    ],
+    'Prefixed metric to 2-character prefixed metric, same unit' => [
+        1000.0,
+        100.0,
+        'hl',
+        'dal',
+    ],
+    'Imperial to Imperial (distance)' => [
+        1.0,
+        3.0,
+        'ft',
+        'yd',
+    ],
     [
         20,
         68,
@@ -38,111 +92,129 @@
         'F',
     ],
     [
-        295.14999999999998,
+        -273.15,
+        0,
+        'K',
+        'C',
+    ],
+    [
+        -459.67,
+        0,
+        'K',
+        'F',
+    ],
+    [
+        295.15,
         22,
         'C',
         'K',
     ],
     [
         22.5,
-        295.64999999999998,
+        295.65,
         'K',
         'C',
     ],
-    [
-        '#N/A',
-        2.5,
-        'ft',
-        'sec',
-    ],
-    [
-        12.345000000000001,
-        12345,
-        'm',
-        'km',
+    'Melting Point of Titanium (K to C)' => [
+        1667.85,
+        1941,
+        'K',
+        'C',
     ],
-    [
-        12345,
-        12.345000000000001,
-        'km',
-        'm',
+    'Melting Point of Titanium (K to F)' => [
+        3034.13,
+        1941,
+        'K',
+        'F',
     ],
-    [
-        0.62137119223732995,
-        1,
-        'km',
-        'mi',
+    'Melting Point of Titanium (K to Rankine)' => [
+        3493.8,
+        1941,
+        'K',
+        'Rank',
     ],
-    [
-        '#VALUE!',
-        'three',
-        'ft',
-        'yds',
+    'Melting Point of Titanium (K to Réaumur)' => [
+        1334.28,
+        1941,
+        'K',
+        'Reau',
     ],
-    [
+    'Temperature synonyms (K)' => [
         123.45,
         123.45,
         'K',
         'kel',
     ],
-    [
+    'Temperature synonyms (C)' => [
         123.45,
         123.45,
         'C',
         'cel',
     ],
-    [
+    'Temperature synonyms (F)' => [
         123.45,
         123.45,
         'F',
         'fah',
     ],
-    [
+    'Invalid value to conver' => [
+        '#VALUE!',
+        'three',
+        'ft',
+        'yds',
+    ],
+    'Prefixed metric to binary prefixed metric' => [
+        '#N/A',
+        12.345,
+        'um',
+        'kiang',
+    ],
+    'Mismatched categories' => [
         '#N/A',
         1,
         'ft',
         'day',
     ],
-    [
-        123.45,
-        123.45,
-        'm',
-        'm',
-    ],
-    [
-        234.56,
-        234.56,
-        'km',
-        'km',
-    ],
-    [
+    'From Prefixed imperial (Invalid)' => [
         '#N/A',
         234.56,
         'kpt',
         'lt',
     ],
-    [
+    'To prefixed imperial (Invalid)' => [
         '#N/A',
         234.56,
-        'sm',
-        'm',
+        'lt',
+        'kpt',
     ],
-    [
+    'Invalid from unit' => [
         '#N/A',
         234.56,
-        'lt',
-        'kpt',
+        'xxxx',
+        'm',
     ],
-    [
+    'Invalid to unit' => [
         '#N/A',
         234.56,
         'm',
-        'sm',
+        'xxxx',
     ],
-    [
-        12345000,
-        12.345000000000001,
-        'km',
-        'mm',
+    'Basic Information conversion' => [
+        2,
+        16,
+        'bit',
+        'byte',
+    ],
+    'Information with standard metric prefix' => [
+        1000,
+        1,
+        'kbyte',
+        'byte',
+    ],
+    'Information with binary prefix' => [
+        1024,
+        1,
+        'kibyte',
+        'byte',
     ],
 ];