diff --git a/src/si/electrical_conductance.rs b/src/si/electrical_conductance.rs
new file mode 100644
index 00000000..86ae2b5e
--- /dev/null
+++ b/src/si/electrical_conductance.rs
@@ -0,0 +1,100 @@
+//! Electrical conductance
+//! (base unit siemens, m<sup>-2</sup> · kg<sup>-1</sup> · s<sup>3</sup> · A<sup>2</sup>).
+
+quantity! {
+    /// Electrical conductance (base unit siemens,
+    /// m<sup>-2</sup> · kg<sup>-1</sup> · s<sup>3</sup> · A<sup>2</sup>).
+    quantity: ElectricalConductance; "electrical conductance";
+    /// Electrical conductance dimension,
+    /// m<sup>-2</sup> · kg<sup>-1</sup> · s<sup>3</sup> · A<sup>2</sup>.
+    dimension: ISQ<
+        N2,     // length
+        N1,     // mass
+        P3,     // time
+        P2,     // electric current
+        Z0,     // thermodynamic temperature
+        Z0,     // amount of substance
+        Z0>;    // luminous intensity
+    units {
+        @yottasiemens: prefix!(yotta); "YS", "yottasiemens", "yottasiemens";
+        @zettasiemens: prefix!(zetta); "ZS", "zettasiemens", "zettasiemens";
+        @exasiemens: prefix!(exa); "ES", "exasiemens", "exasiemens";
+        @petasiemens: prefix!(peta); "PS", "petasiemens", "petasiemens";
+        @terasiemens: prefix!(tera); "TS", "terasiemens", "terasiemens";
+        @gigasiemens: prefix!(giga); "GS", "gigasiemens", "gigasiemens";
+        @megasiemens: prefix!(mega); "MS", "megasiemens", "megasiemens";
+        @kilosiemens: prefix!(kilo); "kS", "kilosiemens", "kilosiemens";
+        @hectosiemens: prefix!(hecto); "hS", "hectosiemens", "hectosiemens";
+        @decasiemens: prefix!(deca); "daS", "decasiemens", "decasiemens";
+        /// Derived unit of electrical conductance.
+        @siemens: prefix!(none); "S", "siemens", "siemens";
+        @mho: prefix!(none); "S", "mho", "mhos";
+        @decisiemens: prefix!(deci); "dS", "decisiemens", "decisiemens";
+        @centisiemens: prefix!(centi); "cS", "centisiemens", "centisiemens";
+        @millisiemens: prefix!(milli); "mS", "millisiemens", "millisiemens";
+        @microsiemens: prefix!(micro); "µS", "microsiemens", "microsiemens";
+        @nanosiemens: prefix!(nano); "nS", "nanosiemens", "nanosiemens";
+        @picosiemens: prefix!(pico); "pS", "picosiemens", "picosiemens";
+        @femtosiemens: prefix!(femto); "fS", "femtosiemens", "femtosiemens";
+        @attosiemens: prefix!(atto); "aS", "attosiemens", "attosiemens";
+        @zeptosiemens: prefix!(zepto); "zS", "zeptosiemens", "zeptosiemens";
+        @yoctosiemens: prefix!(yocto); "yS", "yoctosiemens", "yoctosiemens";
+
+        @abmho: 1.0_E9; "abmho", "abmho", "abmhos";
+        @absiemens: 1.0_E9; "abS", "abmsiemens", "abmsiemens";
+        @statsiemens: 1.112_650_E-12; "statS", "statsiemens", "statsiemens";
+        @statmho: 1.112_650_E-12; "statmho", "statmho", "statmhos";
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    storage_types! {
+        use num::One;
+        use si::quantities::*;
+        use si::electrical_resistance as r;
+        use si::electrical_conductance as g;
+        use tests::Test;
+
+        #[test]
+        fn check_dimension() {
+            let _: ElectricalConductance<V> = V::one()
+                / ElectricalResistance::new::<r::ohm>(V::one());
+        }
+
+        #[test]
+        fn check_units() {
+            test::<r::yoctoohm, g::yottasiemens>();
+            test::<r::zeptoohm, g::zettasiemens>();
+            test::<r::attoohm, g::exasiemens>();
+            test::<r::femtoohm, g::petasiemens>();
+            test::<r::picoohm, g::terasiemens>();
+            test::<r::nanoohm, g::gigasiemens>();
+            test::<r::microohm, g::megasiemens>();
+            test::<r::milliohm, g::kilosiemens>();
+            test::<r::centiohm, g::hectosiemens>();
+            test::<r::deciohm, g::decasiemens>();
+            test::<r::ohm, g::siemens>();
+            test::<r::decaohm, g::decisiemens>();
+            test::<r::hectoohm, g::centisiemens>();
+            test::<r::kiloohm, g::millisiemens>();
+            test::<r::megaohm, g::microsiemens>();
+            test::<r::gigaohm, g::nanosiemens>();
+            test::<r::teraohm, g::picosiemens>();
+            test::<r::petaohm, g::femtosiemens>();
+            test::<r::exaohm, g::attosiemens>();
+            test::<r::zettaohm, g::zeptosiemens>();
+            test::<r::yottaohm, g::yoctosiemens>();
+
+            test::<r::abohm, g::absiemens>();
+            test::<r::statohm, g::statsiemens>();
+            test::<r::abohm, g::abmho>();
+            test::<r::statohm, g::statmho>();
+
+            fn test<R: r::Conversion<V>, G: g::Conversion<V>>() {
+                Test::assert_approx_eq(&ElectricalConductance::new::<G>(V::one()),
+                    &(V::one() / ElectricalResistance::new::<R>(V::one())));
+            }
+        }
+    }
+}
diff --git a/src/si/mod.rs b/src/si/mod.rs
index c165659b..b8237ad9 100644
--- a/src/si/mod.rs
+++ b/src/si/mod.rs
@@ -28,6 +28,7 @@ system! {
         capacitance::Capacitance,
         density::Density,
         electrical_resistance::ElectricalResistance,
+        electrical_conductance::ElectricalConductance,
         electric_current::ElectricCurrent,
         electric_potential::ElectricPotential,
         energy::Energy,