Conversions

Watts to Amps Calculator

Need to know the current a device draws? This calculator converts watts to amps using your voltage and, for AC, the power factor.

Your details

W
V

Common: 120 V (US), 230 V (EU/UK), 12 V (car/DC).

Use 1 for DC and resistive loads; 0.8 for many motors.

Results

Current
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Last updated June 30, 2026. Results update automatically as you type.

How it works

Amps = watts ÷ (volts × power factor). For DC or purely resistive loads (heaters, incandescent bulbs) the power factor is 1. Motors and some electronics have a lower power factor, which increases the current drawn.

Frequently asked questions

What voltage should I use?

Use your local mains voltage — about 120 V in North America and 230 V in Europe and the UK. For car or battery circuits, use the DC voltage (often 12 V).

What is power factor?

It describes how effectively current is converted to useful power in AC circuits. Resistive loads are 1.0; motors and some electronics are lower (e.g. 0.8).

Why does this matter?

Knowing the amps helps you choose the right fuse, breaker, cable and whether a circuit can safely handle a device.

These calculators provide general estimates for educational purposes only and are not financial advice. Real-world results depend on factors not captured here. Verify figures independently before making any purchase or financial decision.

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