Electric Conductance Converter

Electric conductance is the reciprocal of electric resistance — it measures how easily electric current flows through a component or material. While resistance describes opposition to current flow, conductance describes facilitation of current flow. The relationship G = 1/R (where G is conductance and R is resistance) is fundamental to circuit analysis, particularly in parallel circuit analysis where conductances add directly, unlike resistances in parallel which require the reciprocal sum formula.

The SI unit of electric conductance is the siemens (S), named after German engineer Werner von Siemens. One siemens equals one ampere per volt (A/V), meaning a conductance of 1 S allows a current of 1 A to flow with a driving voltage of 1 V. The siemens is also equivalent to one reciprocal ohm (Ω⁻¹ = 1/Ω), and its larger and smaller prefixed variants — megasiemens (MS), kilosiemens (kS), millisiemens (mS), and microsiemens (µS) — cover the full range of practical conductance values.

The mho is simply an older name for the siemens, created by spelling "ohm" backwards. The mho was the standard unit of conductance in the United States for much of the 20th century before the 1971 adoption of the siemens by the SI. Old Tektronix oscilloscopes, HP impedance analyzers, and vintage analog multimeters still display conductance in mhos. One mho equals one siemens exactly, making conversion trivial — the choice between them is purely historical and regional convention.

For water quality and chemical analysis, the microsiemens (µS) is the dominant unit. The electrical conductivity of aqueous solutions is proportional to their ionic concentration, making conductance measurement a rapid, non-destructive way to assess water purity. Environmental regulations specify maximum conductance thresholds for drinking water (typically 500–1000 µS/cm), irrigation water, and industrial process water. The related millisiemens (mS) is used for more conductive solutions like culture media, biological fluids, and seawater.

In electrochemistry, the kilosiemens (kS) scale is encountered in electrode characterisation and ionic conductivity of melts. Molten salts used in aluminium smelting and some battery electrolytes can have conductivities on the order of kilosiemens per meter. The ampere/volt (A/V) unit is functionally identical to the siemens and appears in some circuit analysis textbooks that prefer to express all electrical quantities in terms of fundamental units rather than named derived units.

The CGS units of conductance include the abmho (EMU, = 10⁹ S) and the statmho (ESU, ≈ 1.113 × 10⁻¹² S). The gemmho and micromho are obsolete names for the micromho (= 1 µS = 10⁻⁶ S), used in older American engineering texts. The abmho's enormous size (one billion siemens) reflects the CGS-EMU system's architecture, while the statmho's tiny size (about one picosiemens) reflects the ESU system.

The Quantized Hall conductance (e²/h ≈ 3.874 × 10⁻⁵ S) is the conductance quantum — the fundamental unit that appears in quantum transport. Each quantised conductance channel in a nanoscale conductor or quantum point contact contributes exactly one conductance quantum. This quantity is the inverse of the von Klitzing constant (the Quantized Hall Resistance) and is used as a resistance/conductance standard in quantum metrology.

This converter supports all twelve electric conductance units: siemens [S], megasiemens [MS], kilosiemens [kS], millisiemens [mS], microsiemens [µS], ampere/volt [A/V], mho, gemmho, micromho, abmho, statmho, and Quantized Hall conductance. Select your units, enter a value, and get an instant conversion. Unit Converters Lab is the fastest, most accurate online tool for all your electrical unit conversion needs.