Conductance Calculator
Calculate electrical conductance in Siemens (S) from resistance, voltage, and current. Convert resistance to conductance, find conductance from voltage and current, and analyze AC circuits with admittance. Perfect for electronics, electrical engineering, and circuit analysis.
What Is Conductance?
Conductance is the measure of how easily electricity flows through a material or component. It is the reciprocal of resistance — the opposite of resistance. While resistance opposes the flow of current, conductance facilitates it.
G = 1 / R
Where:
G = Conductance (siemens, S)
R = Resistance (ohms, Ω)
Alternative formula: G = I / V (from Ohm's Law)
The unit of conductance is the siemen (S), named after the German inventor Ernst Werner von Siemens. One siemen is defined as one ampere per volt (A/V) — the conductance of a component that allows 1 ampere of current to flow when 1 volt is applied. In older literature, conductance was sometimes expressed in mhos (ohm spelled backwards).
How Does the Conductance Calculator Work?
This calculator supports three modes:
- Resistance → Conductance: Enter a resistance value to find its conductance. The formula is G = 1/R.
- Voltage & Current: Enter voltage and current to calculate conductance using G = I / V.
- AC Admittance: Enter resistance and reactance to calculate the admittance (Y) of an AC circuit, where Y = 1 / (R + jX).
The calculator also displays the relationship between conductance and resistance, and optionally calculates conductivity (σ) when length and cross-sectional area are provided.
Why Use This Conductance Calculator?
- Three Modes: Supports resistance-to-conductance, voltage-current, and AC admittance calculations.
- Unit Flexibility: Choose between standard units and metric prefixes (kΩ, mV, mA).
- Conductivity Option: Calculate conductivity (S/m) with length and area inputs.
- Visual Breakdown: A chart shows the conductance-resistance relationship.
- Free & Private: No registration, no data storage.
Conductance vs. Resistance
- Resistance (R): Measures opposition to current flow. Higher resistance = less current.
- Conductance (G): Measures ease of current flow. Higher conductance = more current.
- Relationship: They are reciprocals: G = 1/R and R = 1/G.
- Units: Resistance in ohms (Ω), conductance in siemens (S).
- Parallel Circuits: Conductances add directly, while resistances add reciprocally.
❓ Conductance Calculator FAQ
What is conductance?
Conductance is the measure of how easily electricity flows through a material. It is the reciprocal of resistance. The unit of conductance is the siemen (S).
How do I calculate conductance from resistance?
Use the formula G = 1/R. For example, if R = 100 Ω, then G = 1/100 = 0.01 S (10 mS).
How do I calculate conductance from voltage and current?
Use the formula G = I / V. For example, if V = 12 V and I = 2 A, then G = 2/12 = 0.1667 S.
What is the unit of conductance?
The unit of conductance is the siemen (S), also known as the mho (℧). One siemen equals one ampere per volt (A/V).
What is the difference between conductance and conductivity?
Conductance (G) is the measure of how easily a specific component allows current flow. Conductivity (σ) is an intrinsic property of a material that describes how well it conducts electricity, independent of its geometry. Conductivity is measured in siemens per meter (S/m).
What is admittance in AC circuits?
Admittance (Y) is the AC equivalent of conductance. It is the reciprocal of impedance (Z). Y = 1/Z = 1/(R + jX), where R is resistance and X is reactance. Admittance is measured in siemens (S).
What is the relationship between conductance and resistance?
They are reciprocals: G = 1/R and R = 1/G. High resistance means low conductance, and vice versa.
How do I convert siemens to mhos?
Siemens and mhos are the same unit. 1 S = 1 ℧. The term "mho" is simply ohm spelled backwards.
What is a millisiemens (mS)?
A millisiemens (mS) is one-thousandth of a siemen. 1 mS = 0.001 S. Many conductance values in electronics are in the millisiemens range.
How do I calculate conductivity from conductance?
Conductivity (σ) = G × (L / A), where L is the length and A is the cross-sectional area. The calculator can do this for you when you provide the dimensions.
What is the conductance of a short circuit?
A short circuit has zero resistance, so its conductance is infinite (G = 1/0 → ∞). In practice, it's very high.
What is the conductance of an open circuit?
An open circuit has infinite resistance, so its conductance is zero (G = 1/∞ = 0).
How do I calculate total conductance in a parallel circuit?
In a parallel circuit, total conductance is the sum of individual conductances: Gtotal = G₁ + G₂ + G₃ + ... This is the reciprocal of total resistance.
What is the relationship between conductance and Ohm's Law?
Ohm's Law states V = I × R. Since G = 1/R, it can also be written as I = V × G. This form is often used in circuit analysis.
What is the conductance of a 1kΩ resistor?
G = 1/1000 = 0.001 S = 1 mS. A 1 kΩ resistor has a conductance of 1 millisiemen.
What is the conductance of a 10Ω resistor?
G = 1/10 = 0.1 S = 100 mS. A 10 Ω resistor has a conductance of 100 millisiemens.
What is the conductance of a 1MΩ resistor?
G = 1/1,000,000 = 0.000001 S = 1 µS. A 1 MΩ resistor has a conductance of 1 microsiemen.
Can I use this calculator for AC circuits?
Yes. The AC Admittance mode calculates the admittance (Y) of an AC circuit from resistance and reactance. This is useful for analyzing AC circuits.