Electricity

Electrical Power Calculator

Calculate watts from voltage, current and power factor.

What power factor adds

Basic calculators often multiply volts by amps only. This page also includes power factor, so AC users can distinguish apparent power in volt-amperes from real power in watts.

Example

At 230 V and 10 A with a power factor of 1, real power is 2,300 W. With a 0.8 power factor, real power is 1,840 W while apparent power remains 2,300 VA.

Common mistakes

Do not use watts alone to size wiring, breakers or electrical protection. For AC equipment, check nameplate ratings and local electrical requirements.

Limitations

Electrical systems can be dangerous. This calculator does not check breaker sizing, wiring, phase configuration, local electrical codes or manufacturer ratings.

Last reviewed: 2026-05-17

Before relying on this result

Use this calculator together with the formula, assumptions, limitations and examples on the page. If the topic involves health, tax, lending, investment, legal, safety or current-rate decisions, treat the number as an estimate and check the relevant primary source or professional guidance.

Calculator metadata last reviewed: 2026-05-14.