QuickCheckToolsAmps to watts calculator
Convert current in amps to power in watts for DC, AC single-phase and three-phase supplies.
Amps to watts chart
Power factor 1 (DC, heaters, kettles).
| Amps | 12 V | 120 V | 230 V | 240 V |
|---|---|---|---|---|
| 1 A | 12 W | 120 W | 230 W | 240 W |
| 5 A | 60 W | 600 W | 1,150 W | 1,200 W |
| 10 A | 120 W | 1,200 W | 2,300 W | 2,400 W |
| 13 A | 156 W | 1,560 W | 2,990 W | 3,120 W |
| 15 A | 180 W | 1,800 W | 3,450 W | 3,600 W |
| 20 A | 240 W | 2,400 W | 4,600 W | 4,800 W |
| 30 A | 360 W | 3,600 W | 6,900 W | 7,200 W |
Need the reverse? Use the watts to amps calculator.
Questions
How do I convert amps to watts?
For DC, multiply amps by volts: 10 A at 120 V is 1,200 W. For AC single-phase, also multiply by the power factor. For three-phase, multiply √3 × power factor × amps × the line-to-line voltage.
How many watts is 13 amps at 230 volts?
2,990 watts, about 3 kW, which is why UK 13 A plugs are used for appliances up to around 3 kW.
How many watts can a 15 amp circuit handle?
15 A × 120 V is 1,800 W. Electricians usually keep continuous loads to 80% of that (1,440 W), but check with a qualified electrician for your circuit.
What is power factor?
For AC equipment, power factor (0 to 1) describes how much of the current does useful work. Heaters are close to 1; motors are often 0.8–0.9. Using 1 gives the maximum watts.
Can I use this to size a fuse, breaker or cable?
No. This converts between amps and watts only. Sizing circuits depends on wiring regulations, cable type, length and installation, so ask a qualified electrician.
What voltage should I use?
120 V for US and Canadian household outlets, 230 V in the UK and most of Europe. Check the rating plate on the equipment.
For conversion only, not for sizing cables, fuses or breakers. Electrical installation work should follow your local wiring regulations.