Electrical reference tools · No account
Watts to Amps Calculator
Convert real electrical power in W or kW to current for DC, single-phase AC or balanced three-phase AC using voltage and power factor.
Formula and units
DC: I = P / V. Single phase: I = P / (V × PF). Balanced three phase: I = P / (√3 × V × PF).
How to use these results
Use RMS voltage for AC; three-phase voltage is line-to-line and the result is line current. Enter real input power, not motor output power or apparent VA. Power factor is required for AC. This estimate does not size a breaker or cable.
Verify critical electrical work with a qualified professional and applicable manufacturer instructions.
Worked example
A 1,500 W resistive load at 120 V draws 12.5 A. At PF 0.8, the same real single-phase power draws 15.625 A.
Reference
Formula background: Fluke — Electrical measurements: units, devices and formulas. The assumptions and input validation above define this calculator’s scope.
