Watts, Volts & Amps Calculator

Convert between watts, volts and amps for DC, single-phase and three-phase AC circuits.

Supply	AC single-phase
Find	Amps
Power	2,000 W
Voltage (line-to-line for 3-phase)	230 V
Power factor	1

Supply

Find

Power

Voltage (line-to-line for 3-phase)

Power factor

1 for resistive loads; 0.8–0.95 for motors.

Current

8.6957 A

2 kW at 230 V draws 8.6957 A (apparent power 2 kVA).

Current for 2 kW at common voltages

12 V166.6667 A
24 V83.3333 A
120 V16.6667 A
230 V8.6957 A
240 V8.3333 A
400 V5 A

About the Watts, Volts & Amps Calculator

Choose DC, single-phase or three-phase AC, what you want to find, and enter the other values with the power factor for AC. The calculator gives watts, amps, volts and apparent power.

For DC, power = volts × amps. For AC, multiply by the power factor (real power ÷ apparent power); three-phase circuits also multiply by √3 using line-to-line voltage. A 2,000 W kettle on 230 V draws about 8.7 A; on 120 V about 16.7 A.

The formula

DC: P = V I; 1-phase: P = V I PF; 3-phase: P = √3 V I PF

Worked example

A 2,000 W kettle on 230 V single-phase, power factor 1

I = 2,000 ÷ 230
= 8.70 A
On 120 V it would draw 16.7 A

Questions people ask

What is power factor?

The ratio of real to apparent power; motors and some electronics have PF below 1.

How many amps can a socket supply?

Typically 13 A (UK), 15–20 A (US), 16 A (EU); check your circuit.