diff --git a/src/constants/numerical.js b/src/constants/numerical.js
index 6b0d6b55ed2..ac18cf60ee3 100644
--- a/src/constants/numerical.js
+++ b/src/constants/numerical.js
@@ -47,5 +47,11 @@ module.exports = {
     /*
      * Are two values nearly equal? Compare to 1PPM
      */
-    ALMOST_EQUAL: 1 - 1e-6
+    ALMOST_EQUAL: 1 - 1e-6,
+
+    /*
+     * not a number, but for displaying numbers: the "minus sign" symbol is
+     * wider than the regular ascii dash "-"
+     */
+    MINUS_SIGN: '\u2212'
 };
diff --git a/src/plots/cartesian/axes.js b/src/plots/cartesian/axes.js
index 8a25ad031c4..c2009959aa3 100644
--- a/src/plots/cartesian/axes.js
+++ b/src/plots/cartesian/axes.js
@@ -27,6 +27,7 @@ var ONEDAY = constants.ONEDAY;
 var ONEHOUR = constants.ONEHOUR;
 var ONEMIN = constants.ONEMIN;
 var ONESEC = constants.ONESEC;
+var MINUS_SIGN = constants.MINUS_SIGN;
 
 var MID_SHIFT = require('../../constants/alignment').MID_SHIFT;
 
@@ -1055,7 +1056,7 @@ function autoTickRound(ax) {
 
         var rangeexp = Math.floor(Math.log(maxend) / Math.LN10 + 0.01);
         if(Math.abs(rangeexp) > 3) {
-            if(ax.exponentformat === 'SI' || ax.exponentformat === 'B') {
+            if(isSIFormat(ax.exponentformat) && !beyondSI(rangeexp)) {
                 ax._tickexponent = 3 * Math.round((rangeexp - 1) / 3);
             }
             else ax._tickexponent = rangeexp;
@@ -1299,12 +1300,13 @@ function formatLog(ax, out, hover, extraPrecision, hideexp) {
         out.text = numFormat(Math.pow(10, x), ax, hideexp, extraPrecision);
     }
     else if(isNumeric(dtick) || ((dtick.charAt(0) === 'D') && (Lib.mod(x + 0.01, 1) < 0.1))) {
-        if(['e', 'E', 'power'].indexOf(ax.exponentformat) !== -1) {
-            var p = Math.round(x);
+        var p = Math.round(x);
+        if(['e', 'E', 'power'].indexOf(ax.exponentformat) !== -1 ||
+                (isSIFormat(ax.exponentformat) && beyondSI(p))) {
             if(p === 0) out.text = 1;
             else if(p === 1) out.text = '10';
             else if(p > 1) out.text = '10<sup>' + p + '</sup>';
-            else out.text = '10<sup>\u2212' + -p + '</sup>';
+            else out.text = '10<sup>' + MINUS_SIGN + -p + '</sup>';
 
             out.fontSize *= 1.25;
         }
@@ -1359,6 +1361,21 @@ function formatLinear(ax, out, hover, extraPrecision, hideexp) {
 // also automatically switch to sci. notation
 var SIPREFIXES = ['f', 'p', 'n', 'μ', 'm', '', 'k', 'M', 'G', 'T'];
 
+function isSIFormat(exponentFormat) {
+    return exponentFormat === 'SI' || exponentFormat === 'B';
+}
+
+// are we beyond the range of common SI prefixes?
+// 10^-16 -> 1x10^-16
+// 10^-15 -> 1f
+// ...
+// 10^14 -> 100T
+// 10^15 -> 1x10^15
+// 10^16 -> 1x10^16
+function beyondSI(exponent) {
+    return exponent > 14 || exponent < -15;
+}
+
 function numFormat(v, ax, fmtoverride, hover) {
         // negative?
     var isNeg = v < 0,
@@ -1387,7 +1404,7 @@ function numFormat(v, ax, fmtoverride, hover) {
         if(ax.hoverformat) tickformat = ax.hoverformat;
     }
 
-    if(tickformat) return d3.format(tickformat)(v).replace(/-/g, '\u2212');
+    if(tickformat) return d3.format(tickformat)(v).replace(/-/g, MINUS_SIGN);
 
     // 'epsilon' - rounding increment
     var e = Math.pow(10, -tickRound) / 2;
@@ -1436,14 +1453,14 @@ function numFormat(v, ax, fmtoverride, hover) {
 
     // add exponent
     if(exponent && exponentFormat !== 'hide') {
+        if(isSIFormat(exponentFormat) && beyondSI(exponent)) exponentFormat = 'power';
+
         var signedExponent;
-        if(exponent < 0) signedExponent = '\u2212' + -exponent;
+        if(exponent < 0) signedExponent = MINUS_SIGN + -exponent;
         else if(exponentFormat !== 'power') signedExponent = '+' + exponent;
         else signedExponent = String(exponent);
 
-        if(exponentFormat === 'e' ||
-                ((exponentFormat === 'SI' || exponentFormat === 'B') &&
-                 (exponent > 12 || exponent < -15))) {
+        if(exponentFormat === 'e') {
             v += 'e' + signedExponent;
         }
         else if(exponentFormat === 'E') {
@@ -1455,7 +1472,7 @@ function numFormat(v, ax, fmtoverride, hover) {
         else if(exponentFormat === 'B' && exponent === 9) {
             v += 'B';
         }
-        else if(exponentFormat === 'SI' || exponentFormat === 'B') {
+        else if(isSIFormat(exponentFormat)) {
             v += SIPREFIXES[exponent / 3 + 5];
         }
     }
@@ -1463,11 +1480,10 @@ function numFormat(v, ax, fmtoverride, hover) {
     // put sign back in and return
     // replace standard minus character (which is technically a hyphen)
     // with a true minus sign
-    if(isNeg) return '\u2212' + v;
+    if(isNeg) return MINUS_SIGN + v;
     return v;
 }
 
-
 axes.subplotMatch = /^x([0-9]*)y([0-9]*)$/;
 
 // getSubplots - extract all combinations of axes we need to make plots for
diff --git a/test/jasmine/tests/axes_test.js b/test/jasmine/tests/axes_test.js
index b76259e1e48..0367649a9e1 100644
--- a/test/jasmine/tests/axes_test.js
+++ b/test/jasmine/tests/axes_test.js
@@ -1929,6 +1929,112 @@ describe('Test axes', function() {
             });
         }
 
+        it('reverts to "power" for SI/B exponentformat beyond the prefix range (linear case)', function() {
+            var textOut = mockCalc({
+                type: 'linear',
+                tickmode: 'linear',
+                exponentformat: 'B',
+                showexponent: 'all',
+                tick0: 0,
+                dtick: 1e13,
+                range: [8.5e13, 11.5e13]
+            });
+
+            expect(textOut).toEqual([
+                '90T', '100T', '110T'
+            ]);
+
+            textOut = mockCalc({
+                type: 'linear',
+                tickmode: 'linear',
+                exponentformat: 'B',
+                showexponent: 'all',
+                tick0: 0,
+                dtick: 1e14,
+                range: [8.5e14, 11.5e14]
+            });
+
+            expect(textOut).toEqual([
+                '0.9×10<sup>15</sup>',
+                '1×10<sup>15</sup>',
+                '1.1×10<sup>15</sup>'
+            ]);
+
+            textOut = mockCalc({
+                type: 'linear',
+                tickmode: 'linear',
+                exponentformat: 'SI',
+                showexponent: 'all',
+                tick0: 0,
+                dtick: 1e-16,
+                range: [8.5e-16, 11.5e-16]
+            });
+
+            expect(textOut).toEqual([
+                '0.9f', '1f', '1.1f'
+            ]);
+
+            textOut = mockCalc({
+                type: 'linear',
+                tickmode: 'linear',
+                exponentformat: 'SI',
+                showexponent: 'all',
+                tick0: 0,
+                dtick: 1e-17,
+                range: [8.5e-17, 11.5e-17]
+            });
+
+            expect(textOut).toEqual([
+                '0.9×10<sup>\u221216</sup>',
+                '1×10<sup>\u221216</sup>',
+                '1.1×10<sup>\u221216</sup>'
+            ]);
+        });
+
+        it('reverts to "power" for SI/B exponentformat beyond the prefix range (log case)', function() {
+            var textOut = mockCalc({
+                type: 'log',
+                tickmode: 'linear',
+                exponentformat: 'B',
+                showexponent: 'all',
+                tick0: 0,
+                dtick: 1,
+                range: [-18.5, 18.5]
+            });
+
+            expect(textOut).toEqual([
+                '10<sup>\u221218</sup>',
+                '10<sup>\u221217</sup>',
+                '10<sup>\u221216</sup>',
+                '1f', '10f', '100f', '1p', '10p', '100p', '1n', '10n', '100n',
+                '1μ', '10μ', '100μ', '0.001', '0.01', '0.1', '1', '10', '100',
+                '1000', '10k', '100k', '1M', '10M', '100M', '1B', '10B', '100B',
+                '1T', '10T', '100T',
+                '10<sup>15</sup>',
+                '10<sup>16</sup>',
+                '10<sup>17</sup>',
+                '10<sup>18</sup>'
+            ]);
+
+            textOut = mockCalc({
+                type: 'log',
+                tickmode: 'linear',
+                exponentformat: 'SI',
+                showexponent: 'all',
+                tick0: 0,
+                dtick: 'D2',
+                range: [7.9, 12.1]
+            });
+
+            expect(textOut).toEqual([
+                '100M', '2', '5',
+                '1G', '2', '5',
+                '10G', '2', '5',
+                '100G', '2', '5',
+                '1T'
+            ]);
+        });
+
         it('provides a new date suffix whenever the suffix changes', function() {
             var ax = {
                 type: 'date',