500 Watts to Amps — How Many Amps Is 500 Watts?
500 Watts equals 4.17 amps at 120V or 2.08 amps at 240V. Common 500W devices: Window fan, small power tool, washing machine.
500 Watts Amps at Every Voltage
| Voltage | Single Phase | Three Phase |
|---|---|---|
| 120V | 4.17A | 2.41A |
| 208V | 2.40A | 1.39A |
| 240V | 2.08A | 1.20A |
| 277V | 1.81A | 1.04A |
| 480V | 1.04A | 0.60A |
The Formula
Single Phase: Amps = Watts ÷ Volts. For 500 Watts at 120V: 500 ÷ 120 = 4.17A.
Three Phase: Amps = Watts ÷ (Volts × 1.732). For 500 Watts at 240V 3-phase: 500 ÷ (240 × 1.732) = 1.20A.
With power factor: Amps = Watts ÷ (Volts × PF). A PF of 0.8 increases the current draw by 25%.
Wire and Breaker for 500 Watts at 120V
At 120V, 500 Watts draws 4.2A. Recommended: 14 AWG copper wire with a 15A breaker per NEC 310.16. For continuous loads (3+ hours), apply 125% rule. Use our Wire Size Calculator for exact sizing.
Common 500W Devices
Window fan, small power tool, washing machine. Always check the device nameplate for exact wattage — rated watts may differ from actual consumption.
Disclaimer: Calculations are for reference. Verify with device nameplate. Consult a licensed electrician for installations.