Watts to Amps Calculator

Convert watts to amps — or amps back to watts — for DC, single-phase and three-phase supplies, including power factor.

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What is the Watts to Amps Calculator?

Watts measure power while amps measure current. Converting between them needs the voltage, and for AC also the power factor.

How to Calculate

For DC/single phase: A = W ÷ (V × PF). For three phase: A = W ÷ (√3 × V × PF). Reverse the formula to get watts from amps.

Formula

A = W ÷ (V × PF) · 3-phase: A = W ÷ (√3 × V × PF)

How to Use

  1. Enter a value and pick the units.
  2. The converted result updates instantly.
  3. Use Copy or Print to save it.

Frequently Asked Questions

What power factor should I use?
Use 1 for DC and purely resistive loads (heaters, filament lamps). Motors and many appliances run at 0.8u20130.95 u2014 check the nameplate.
Why does three phase use u221a3?
In a balanced three-phase system, total power is u221a3 u00d7 line voltage u00d7 line current u00d7 power factor.
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