Electrical Conductivity Converter

Electrical conductivity measures how well a material conducts electricity. Cooper is the reference: 100% IACS = 58.0 MS/m.

Common Electrical Conductivity Conversions

FromTo
1 S/m0.01 S/cm
100 %IACS (copper)~58.0×10⁶ S/m
Aluminum~61 %IACS
Stainless steel~1–3 %IACS

Electrical Conductivity Unit Definitions

Siemens/m (S/m)
SI unit.
mS/cm
Millisiemens per centimeter; common for water quality.
%IACS
Percent of International Annealed Copper Standard; used for metals.

Frequently Asked Questions

Why is copper used for electrical wiring?

Copper has very high conductivity (~58 MS/m = 100 %IACS) combined with good mechanical strength, ductility, and corrosion resistance.

What is the conductivity of seawater?

About 5 S/m (very salty). Fresh water ~0.05 S/m. Ultra-pure water is ~5.5×10⁻⁶ S/m — almost an insulator.

What is %IACS and why is it used?

%IACS (International Annealed Copper Standard) rates conductivity relative to annealed copper = 100%. Aluminum is ~61 %IACS; gold is ~70 %IACS. Used to compare conductor alloys.