Siemens is the SI unit of conductance.
Siemens to Millisiemens Converter — S to mS
Convert Siemens (S) to Millisiemens (mS) using the exact conversion factor (1 siemens = 1,000 millisiemens). See the formula, worked examples, and conversion table.
Siemens to Millisiemens converter
Converter
Electricity Converter
Convert electrical units by family and calculate voltage, current, resistance, power, and energy with context values.
Context values
Some unit families need one extra value for a physically accurate result.
Millisiemens is 0.001 siemens units.
Result = input x 1 / 0.001.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Siemens to Millisiemens
Siemens and Millisiemens both belong to the electricity family — voltage, current, resistance, power, or energy — units that show up constantly when working across the different standards used by household wiring (120V/240V depending on region), automotive electrical systems (12V/24V), and electronics design. Specifically: Siemens is the SI unit of conductance, and millisiemens is 0.001 siemens units.
Formula
millisiemens = siemens × 1000
This factor comes from each unit's defined relationship to the category's base unit: 1 siemens equals 1 base unit, and 1 millisiemens equals 0.001 base units, so dividing one by the other gives the direct siemens-to-millisiemens factor of 1000.
Simple example
1 S × 1000 = 1,000 mS
1 siemens = 1,000 millisiemens.
Real-world example
120 S × 1000 = 120,000 mS
120 siemens = 120,000 millisiemens.
Conversion table
| Siemens (S) | Millisiemens (mS) |
|---|---|
| 1 S | 1,000 mS |
| 5 S | 5,000 mS |
| 12 S | 12,000 mS |
| 24 S | 24,000 mS |
| 120 S | 120,000 mS |
| 240 S | 240,000 mS |
Reverse conversion: Millisiemens to Siemens
1 mS × 0.001 = 0.001 S
1 millisiemens = 0.001 siemens.
siemens = millisiemens × 0.001
For a page dedicated to this direction, see Millisiemens to Siemens.
Understanding the Siemens (S)
Siemens is the SI unit of conductance.
Understanding the Millisiemens (mS)
Millisiemens is 0.001 siemens units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many millisiemens are in 1 siemens?
1 siemens equals 1,000 millisiemens, using the exact defined conversion factor rather than an estimate.
How do I convert siemens to millisiemens?
Multiply the siemens value by 1000. The converter above does this instantly to whatever precision you set.
How do I convert millisiemens back to siemens?
Use the reverse factor: 1 millisiemens equals 0.001 siemens. You can also use the swap control in the converter above to flip the direction instantly.
What is a siemens?
Siemens (S) is a unit of electricity.
What is a millisiemens?
Millisiemens (mS) is a unit of electricity.
Is the siemens to millisiemens conversion exact?
Yes. Both siemens and millisiemens are defined by fixed standards rather than physical artifacts, so the factor of 1000 used above is exact to as many digits as you choose to display.
What's the difference between voltage, current, and resistance?
Voltage (volts) is the electrical potential difference driving current through a circuit. Current (amperes) is the rate of flow of electric charge. Resistance (ohms) is how much a component opposes that flow. They're related by Ohm's law (V = I × R), but they are distinct physical quantities, and this page converts between units of just one of them.