How It Works

The calculator determines electrical power by multiplying voltage by current. This relationship is expressed by the electrical power formula P = V × I.

P = V × I, where P is electrical power in watts (W), V is voltage in volts (V), and I is current in amperes (A).

Example

For example, a circuit operating at 12 V with a current of 3 A has an electrical power of 36 W because P = 12 × 3 = 36 W.

Frequently Asked Questions

What is the formula for electrical power?

Electrical power can be calculated with P = V × I, where P is power in watts, V is voltage in volts, and I is current in amperes.

How do you calculate watts from voltage and current?

Multiply voltage in volts by current in amperes. For example, 12 V × 3 A = 36 W.

What unit is electrical power measured in?

Electrical power is measured in watts (W). One watt is equal to one joule per second.

What is the power of a 12 V circuit drawing 3 A?

The electrical power is 36 W. Using P = V × I, the calculation is 12 × 3 = 36 W.

Can electrical power be calculated from voltage and current?

Yes. When voltage and current are known, multiply them together to calculate electrical power in watts.

What is the relationship between power, voltage, and current?

Electrical power is the product of voltage and current: P = V × I. If resistance is also known, power can be calculated using equivalent forms derived from Ohm's Law.