1 amp to watts
At 120 volts, 1 amp delivers 120 watts; at 240 volts, 240 watts (power factor 1).
1 amp to watts at common voltages
| Voltage | Watts, W |
|---|---|
| 12 V DC | 12 |
| 24 V DC | 24 |
| 120 V | 120 |
| 240 V | 240 |
| 208 V three phase | 360 |
| 480 V three phase | 831 |
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 1 amp to watts
Watts = amps × volts, so 1 amp carries 120 watts on a 120 V circuit and 240 watts on a 240 V circuit. On a 12 V DC system, 1 amp is 12 watts. At a power factor of 0.8, 1 amp at 120 V delivers 96 W.
How much of a 15 or 20 amp circuit 1 amp uses
On a 120 V circuit, a 1 amp load uses 7% of a 15 amp circuit and 5% of a 20 amp circuit. A 1 amp 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. A 1 amp continuous load needs a 15 amp circuit.
Nearby values
| Amps, A | 120 V, W | 240 V, W |
|---|---|---|
| 1 | 120 | 240 |
| 5 | 600 | 1,200 |
| 10 | 1,200 | 2,400 |
| 15 | 1,800 | 3,600 |
| 20 | 2,400 | 4,800 |
| 30 | 3,600 | 7,200 |
Appliances that draw about 1 amp
Amps to watts calculator
1 for heaters and lights; motors and electronics 0.8–0.95
- Current
- 1 A
- Voltage
- 120 V
- Kilowatts
- 0.12 kW
How it is calculated
- Watts = 1 × 120 = 120