500 watts to amps
500 watts is 4.17 amps at 120 volts and 2.08 amps at 240 volts, at a power factor of 1.
500 watts to amps at common voltages
| Voltage | Amps, A |
|---|---|
| 12 V DC | 41.67 |
| 24 V DC | 20.83 |
| 120 V | 4.17 |
| 240 V | 2.08 |
| 208 V three phase | 1.39 |
| 480 V three phase | 0.6 |
The AC and three-phase rows assume a power factor of 1, as for heaters and incandescent lamps. Motors and electronics draw more current for the same watts.
How to convert 500 watts to amps
Amps = watts ÷ volts: 500 W ÷ 120 V = 4.17 A, and 500 W ÷ 240 V = 2.08 A. On three phase, amps = watts ÷ (1.732 × volts): 500 W ÷ (1.732 × 208 V) = 1.39 A per line. At a power factor of 0.8, 500 W at 120 V draws 5.21 A.
How much of a 15 or 20 amp circuit 500 watts uses
On a 120 V circuit, 500 W (4.17 A) uses 28% of a 15 amp circuit and 21% of a 20 amp circuit. A 500 W load that runs for three hours or more should stay within 80% of the circuit rating: 12 A on a 15 amp circuit and 16 A on a 20 amp circuit. At 4.17 A, a 500 W continuous load needs a 15 amp circuit.
Nearby values
| Watts, W | 120 V, A | 240 V, A |
|---|---|---|
| 100 | 0.83 | 0.42 |
| 500 | 4.17 | 2.08 |
| 1,000 | 8.33 | 4.17 |
| 1,500 | 12.5 | 6.25 |
| 2,000 | 16.67 | 8.33 |
| 3,000 | 25 | 12.5 |
Appliances that draw about 500 watts
Watts to amps calculator
1 for heaters and lights; motors and electronics 0.8–0.95
- Power
- 500 W
- Voltage
- 120 V
- Share of a 15 A circuit at this voltage
- 28%
How it is calculated
- Amps = 500 ÷ (120) = 4.17