OhmCalc
Calculate electrical values

P = V×I · P = V²/R · P = I²×R

Calculate resistive electrical power in watts

Calculate ideal dissipated power from voltage and current, voltage and resistance, or current and resistance.

Private browser calculation

Choose the two known quantities

Values stay on this page

Known pair

Voltage + resistance

Enter positive values for the same ideal resistive element. Decimal dots and exact SI prefixes are supported.

Voltage

Resistance

OhmCalc models one ideal resistive DC relationship. It does not design wiring, choose components, analyze AC or reactive circuits, or certify safety.