Electric Conductance Converter
Convert electrical conductance between siemens, megasiemens, kilosiemens, millisiemens and microsiemens, ampere per volt, mho, gemmho, micromho, the CGS units abmho and statmho, and the quantized Hall conductance. Pick two units, enter a value and read the result instantly.
Select two units to see the conversion factor.
This tool converts electrical conductance (S) only. It is the inverse of resistance (Ω), and it is not conductivity (S/m), which is a material property.
Electric Conductance Formula
Every conductance unit is a fixed multiple of the siemens. Result = value × (source factor ÷ target factor). Metric prefixes are exact powers of ten: 1 mS = 0.001 S and 1 µS = 0.000001 S. The mho, an ampere per volt and the reciprocal ohm are all exactly one siemens, and the gemmho and micromho are both one microsiemens. The CGS units are exact too: 1 abmho = 10⁹ S, and 1 statmho = 1 ÷ (c² × 10⁻⁵) S ≈ 1.11265 × 10⁻¹² S. The quantized Hall conductance is e²/h ≈ 3.87405 × 10⁻⁵ S, from the exact SI values of e and h.
What Is Electrical Conductance?
Electrical conductance measures how easily current flows through an object. It is the reciprocal of resistance: G = 1 ÷ R = I ÷ V, the current per volt. The SI unit is the siemens (S), which equals one ampere per volt, or one reciprocal ohm. A 100 Ω resistor has a conductance of 0.01 S, which is 10 mS; a 1 MΩ resistor has 1 µS. Conductances of parallel paths simply add, which is why the unit is convenient in circuit analysis.
Everyday values use prefixes. Transistor transconductance and small-signal parameters are quoted in millisiemens, the conductance of water samples and sensors in microsiemens, and power-system admittances in siemens or kilosiemens. The mho is the old name for the siemens, “ohm” spelled backwards, and is still common in North American texts. The micromho and the gemmho are both one microsiemens; gemmho is an obsolete name from old instrument scales.
The abmho (10⁹ S) and the statmho (about 1.1 × 10⁻¹² S) are the CGS electromagnetic and electrostatic units. The quantized Hall conductance is e²/h, about 38.74 µS, the step size of conductance in the quantum Hall effect. It is the inverse of the von Klitzing constant. It is not the same as the conductance quantum G₀ = 2e²/h used for ballistic conductors, which is twice as large.
Do not confuse conductance with related quantities. Resistance is its reciprocal (Electric Resistance Converter). Conductivity, in S/m, is a property of a material that gives the conductance of a conductor through G = σ × A ÷ L (Electric Conductivity Converter). And resistivity in Ω·m is the reciprocal of conductivity (Electric Resistivity Converter).
Supported Units
This converter supports the following 12 conductance units. The last column gives the value of each unit in the base unit, the siemens. The mho and the ampere per volt equal the siemens, and the gemmho equals the micromho.
| Unit | Symbol | Value in S |
|---|---|---|
| Siemens | S | 1 |
| Megasiemens | MS | 1,000,000 |
| Kilosiemens | kS | 1,000 |
| Millisiemens | mS | 0.001 |
| Microsiemens | µS | 1e-6 |
| Ampere per volt | A/V | 1 |
| Mho | mho | 1 |
| Gemmho | gemmho | 1e-6 |
| Micromho | µmho | 1e-6 |
| Abmho | abmho | 1,000,000,000 |
| Statmho | statmho | 1.112650056e-12 |
| Quantized Hall conductance | e²/h | 3.874045865e-5 |
How to Use the Electric Conductance Converter
- Type the electric conductance in the value box. Decimals and scientific notation such as 0.0025 or 2.5e-3 are accepted.
- Choose the From unit and the To unit.
- The result appears instantly, or press Convert Now. Very large or very small results are shown in scientific notation.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, open Show this value in all units for a full list, and Clear to start again.
Step-by-step by hand
- Find the size of each unit in the common base unit (S): 1 mS = 0.001 S and 1 S = 1 S.
- Divide the source size by the target size to get the conversion factor: 0.001 ÷ 1 = 0.001, so 1 mS = 0.001 S.
- Multiply by your value: 25 mS × 0.001 = 0.025 S.
Conductance of ordinary conductors cannot be negative, so only zero and positive numbers are accepted.
Common Conductance Conversions
- Millisiemens to siemens: 25 mS equals 0.025 S.
- A 100 Ω resistor: its conductance of 10 mS equals 0.01 S.
- Siemens to microsiemens: 1 S equals 1,000,000 µS.
- Mho to siemens: 5 mho equals 5 S.
- Quantum Hall step: 1 e²/h equals 38.74045865 µS.
- CGS to SI: 1 abmho equals 1,000,000,000 S, and 1 statmho equals 1.112650056e-12 S.
Siemens to Other Conductance Units
Quick reference for frequently used values
| Siemens (S) | Millisiemens (mS) | Microsiemens (µS) | Kilosiemens (kS) |
|---|---|---|---|
| 1e-6 | 0.001 | 1 | 1e-9 |
| 0.001 | 1 | 1,000 | 1e-6 |
| 0.01 | 10 | 10,000 | 1e-5 |
| 0.1 | 100 | 100,000 | 0.0001 |
| 1 | 1,000 | 1,000,000 | 0.001 |
| 10 | 10,000 | 10,000,000 | 0.01 |
| 100 | 100,000 | 100,000,000 | 0.1 |
| 1,000 | 1,000,000 | 1,000,000,000 | 1 |
Where and Why This Conversion Is Used
- Circuit analysis: parallel branches add in conductance, and transistor parameters are often given in mS.
- Water and chemical sensors: conductance of a probe cell in µS or mS.
- Power systems: line and shunt admittance in siemens.
- Quantum electronics: conductance steps in the quantum Hall effect and nanowires.
- Reading older sources: mho and micromho in North American data, and CGS texts.
Limitations
- Conductance depends on temperature and on the geometry of the object. A unit conversion does not correct for either.
- For AC circuits, admittance includes a reactive part as well as conductance. This tool converts units of conductance only.
Important Differences Between Related Electrical Measurements
- Conductance, S belongs to one object. Conductivity, S/m belongs to a material. For a uniform conductor, G = σ × A ÷ L. Conductance falls as the conductor gets longer; conductivity does not change.
- Conductance vs resistance: they are reciprocals. Two 10 mS paths in parallel give 20 mS, or 50 Ω, while two 100 Ω resistors in series give 200 Ω.
- Conductance vs resistivity: resistivity in Ω·m is the reciprocal of conductivity, not of conductance.
- Conductance vs admittance: admittance is the AC generalisation, also in siemens, with real part conductance and imaginary part susceptance.
Each converter on this site changes units within one quantity only, and none of them mixes quantities. The related tools are: Charge, Current, Linear Charge Density, Surface Charge Density, Volume Charge Density, Linear Current Density, Surface Current Density, Electric Field Strength, Electric Potential, Electric Resistance, Electric Resistivity, Electric Conductance, Electric Conductivity, Electrostatic Capacitance and Inductance.