Ohm to Siemens Converter

Convert ohm siemens between units instantly. Includes conversion tables, common equivalents, and calculation formulas.

Reviewed by Manoj Kumar, Mathematics Educator

Formula

Siemens = 1 / Ohm | Ohm = 1 / Siemens | I = V / R | P = V^2 / R

Conductance in siemens is the reciprocal of resistance in ohms. This inverse relationship means a low resistance corresponds to high conductance and vice versa. Combined with Ohms Law, if you know the resistance and applied voltage, you can calculate the current (I = V/R) and power dissipation (P = V squared / R).

Worked Examples

Example 1: Resistor to Conductance

Problem:Convert a 470 ohm resistor to siemens and find the current at 5V.

Solution:Conductance = 1 / 470 = 0.002128 S = 2.128 mS\nCurrent = V / R = 5 / 470 = 0.01064 A = 10.64 mA\nPower = V^2 / R = 25 / 470 = 0.05319 W = 53.19 mW

Result:470 Ohm = 2.128 mS, Current at 5V = 10.64 mA

Example 2: Conductance to Resistance

Problem:A sensor has a conductance of 0.5 mS. What is its resistance?

Solution:0.5 mS = 0.0005 S\nResistance = 1 / 0.0005 = 2000 Ohm = 2 kOhm\nAt 12V: Current = 12 / 2000 = 0.006 A = 6 mA

Result:0.5 mS = 2000 Ohm = 2 kOhm

Frequently Asked Questions

What is the siemens unit and how does it relate to the ohm?

The siemens (S) is the SI unit of electrical conductance, named after Ernst Werner von Siemens. It is the reciprocal of the ohm: 1 siemens equals 1 divided by 1 ohm, or equivalently, 1 ampere per volt. If a resistor has 50 ohms of resistance, its conductance is 1/50 = 0.02 siemens or 20 millisiemens. The siemens was formerly called the mho (ohm spelled backward), and some older references still use this term.

How do I convert between different siemens prefixes?

Siemens uses standard metric prefixes. One millisiemens (mS) equals 0.001 siemens, and one microsiemens (uS) equals 0.000001 siemens. To convert millisiemens to microsiemens, multiply by 1000. Water conductivity is typically measured in microsiemens per centimeter: pure water is about 0.055 uS/cm, tap water is 50 to 1500 uS/cm, and seawater is about 50,000 uS/cm.

References

Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy