Electrical Power Calculator

Electrical power is the rate at which electrical energy is transferred or converted. The three equivalent power formulas (P = VI, P = I²R, P = V²/R) allow power to be calculated from any two of the three fundamental quantities (V, I, R)

The calculator uses the standard published formula for power calc. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches, kilowatts, watts. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: P = V × I (power = voltage × current). Each step in the calculation is shown so you can verify the result manually.