How Many Amps Is 500 Watts?
At 120 V DC, 500 watts = 4.1667 A. At 240 V DC, 500 watts = 2.0833 A. For AC circuits, divide by voltage × power factor (e.g. at 120V AC, PF 0.8: 5.2083 A). Use the calculator below for any voltage or circuit type.
500 Watts to Amps — DC Reference Chart
| Voltage | Current (DC) | Application |
|---|---|---|
| 12 V | 41.6667 A | 12V automotive / RV / solar |
| 24 V | 20.8333 A | 24V solar / industrial DC |
| 48 V | 10.4167 A | 48V telecom / e-bike |
| 120 V | 4.1667 A | US household standard |
| 240 V | 2.0833 A | US/EU 240V circuit |
| 480 V | 1.0417 A | Industrial 3-phase (per phase) |
Breaker sizing: At 120V, 500W draws 4.17A — a standard 15A breaker is sufficient. At 240V (2.08A), a 15A breaker is also adequate. Per NEC 210.20, size breakers at 125% of continuous load. Always consult a licensed electrician.
Frequently Asked Questions
How many amps is 500 watts at 120V?
500 watts at 120V DC = 500 ÷ 120 = 4.1667 amps. For AC single-phase with PF 0.8: 500 ÷ (120 × 0.8) = 5.2083 amps. For AC three-phase with PF 0.8 at 120V L-N: 500 ÷ (120 × 0.8 × √3) = 3.0070 amps.
How many amps is 500 watts at 240V?
500 watts at 240V DC = 500 ÷ 240 = 2.0833 amps. For AC single-phase with PF 0.8: 500 ÷ (240 × 0.8) = 2.6042 amps.
What size breaker do I need for 500 watts?
At 120V, 500W draws 4.17A. The NEC requires breakers sized at 125% for continuous loads: 4.17 × 1.25 = 5.21A. The next standard size is a 15A breaker, which is the minimum residential standard and is more than sufficient. At 240V (2.08A), a 15A breaker is also adequate. Always consult a licensed electrician for circuit design.