Electric Power

Calculate electric power from voltage and current, voltage and resistance, or current and resistance. Step-by-step circuit formulas for study and quick checks.

Key formula

P = IV, P = V^2/R, P = I^2R

About this tool

Electric power connects voltage, current, and resistance in several equivalent forms. This calculator helps users pick the right relationship when only two circuit values are known.

How to use this calculator

1. Choose the variable you want to solve for and confirm which values are already known.
2. Enter inputs in consistent units before calculating so the formula is applied correctly.
3. Check whether the result is physically reasonable by comparing it with the size of the inputs.
4. Use the step-by-step breakdown to see how the equation was rearranged and evaluated.