Electrical Power Calculator

Electrical power P = IV tells you how fast a device converts electrical energy. Enter any two of power, current, and voltage to find the third.

How to interpret the result

Power is how fast electrical energy becomes heat, light, or motion. A 100 W bulb on 230 V draws about 0.43 A; the same 100 W on 12 V draws over 8 A — which is why low-voltage wiring needs much thicker cables.

Assumptions

• Steady DC conditions (or resistive AC load)
• Voltage and current in phase for the AC case
• Power is the average rate of energy conversion