How to Calculate Electric Power
Calculate electrical power from voltage, current, or resistance.
The Formula
P = V × I = I²R = V²/RThe electric power formula uses the mathematical relationship: P = V × I = I²R = V²/R. Each variable in the formula represents a measurable quantity that affects the final result.
Step-by-Step Method
- 1Identify all input values needed for the electric power calculation.
- 2Substitute your known values into the formula: P = V × I = I²R = V²/R.
- 3Perform the arithmetic operations in the correct order (PEMDAS/BODMAS).
- 4Check that your result has the correct units and is within a reasonable range.
- 5Verify using the interactive Electric Power Calculator to confirm your answer.
Related Topics
electric powerwattvoltagecurrentphysics
Use the Interactive Calculator
Skip the manual math — get instant results with our free Electric Power calculator.