Electric Units Converter
Calculate voltage, current, power and resistance using Ohm's law.
I know…
Voltage
Current
Voltageinput
— V
— mV— kV
Currentinput
— A
— mA— μA
Resistance
— Ω
— kΩ— MΩ
Power
— W
— mW— kW
Ohm's Law formulas
V = I × R
Voltage
I = V / R
Current
R = V / I
Resistance
P = V × I
Power
P = I² × R
Power
P = V² / R
Power
I = √(P/R)
Current
V = √(P×R)
Voltage
Solve Ohm's Law and power formulas for voltage (V), current (I), resistance (R) and power (P). Enter any two known values to calculate the other two.
Key Features
Six Input Modes
V+I, V+R, V+P, I+R, I+P, R+P — covers every combination of two known electrical quantities.
Unit Selection
Each input supports sub-units: mV/V/kV for voltage, μA/mA/A for current, Ω/kΩ/MΩ for resistance, mW/W/kW/MW for power.
Alternate Units
Each result is shown in base units plus two common sub-unit conversions (e.g. volts also shown as mV and kV).
Ohm's Law Formulas
Built-in formula reference card showing all eight Ohm's Law derivations.
How to Use
- 1Select which two values you know.
- 2Enter the values and choose appropriate units.
- 3The other two quantities are calculated and displayed instantly.