Quickly convert Siemens (S) to Mho (℧). Includes the conversion formula, a quick reference table, and the history of why these two electrical units are identical.
Conductance Converter
The Conversion Formula
The conversion between Siemens (S) and Mho (℧) is the simplest in electrical engineering. Because they are different names for identical units of conductance, the value remains the same.
1 Siemens (S) = 1 Mho (℧)
Conversion Table (Quick Reference)
| Siemens (S) | Mho (℧) |
|---|---|
| 0.001 S (1 mS) | 0.001 ℧ |
| 1 S | 1 ℧ |
| 10 S | 10 ℧ |
| 100 S | 100 ℧ |
Contextual Information
Transitioning from Mho to Siemens
Historically, the unit of conductance was the Mho. The name was chosen because conductance is the reciprocal of resistance, and “Mho” is “Ohm” spelled backward. Its symbol is the inverted Greek letter Omega (℧).
In 1971, the 14th General Conference on Weights and Measures officially adopted the Siemens (S) as the SI unit for conductance, naming it after Werner von Siemens. Despite this change, the term Mho and the symbol ℧ are still frequently used in North America and in vintage electronics documentation.
Why do we use these units?
Conductance measures how easily electricity flows through a circuit. While resistance (measured in Ohms) tells you how much a material stops current, conductance (Siemens/Mho) tells you how much it allows. It is defined as:
G = 1 / R
Where G is conductance and R is resistance.