Watts to Amps Calculator
Converts power in watts to current in amps for DC, AC single-phase and three-phase circuits — pick the circuit type, enter the voltage and power factor, and it solves the current.
Enter Values
Minimum 0
Minimum 0
Minimum 0
Range 0–1
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter any two of power (W), current (A) and voltage (V).
- Press Calculate — the third value is solved.
How it works
Power, current and voltage are linked by W = V × A, so current = power ÷ voltage, power = current × voltage and voltage = power ÷ current.
Worked example
1,200 W at 240 V. = 5 A. And 5 A at 240 V = 1,200 W.
Common mistakes
- Forgetting the power factor on AC motor loads.
- Using the wrong supply voltage (120 V vs 230/240 V).
Frequently asked questions
What's the formula?
Amps = watts ÷ volts for DC or resistive AC. For AC motors, also divide by the power factor.
Which voltage should I use?
Your supply voltage — about 120 V in North America and 230–240 V in Australia, the UK and Europe.
Does this work for three-phase power?
This is single-phase (W = V × A). Three-phase adds a √3 factor and power factor, so use a dedicated three-phase calculator for that.
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- Ohms Law Calculator
- Three Phase Power Calculator
- Power Factor Calculator
- Voltage Drop Calculator
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Cite this tool
Zerdly. (2026). Watts to Amps Calculator. Retrieved from https://www.zerdly.com/tools/watts-to-amps-calculator/
Tip: Enter any known values to calculate the remaining results.
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