Ohm's Law Calculator

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Solve voltage, current, resistance and power instantly. Enter any two values and the calculator works out the other two using Ohm's law and the power equations.

Fill in any two values — the other two are calculated automatically.

V
A
Ω
W
V Voltage I Current R Resistance
Voltage –
VVoltage –
ICurrent –
RResistance –
PPower –
Uses V = I × R and P = V × I (with P = I²R and P = V²/R). Values assume a purely resistive DC circuit at a steady operating temperature.
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