QuickCheckToolsWatts to amps calculator
Convert power in watts to current in amps for DC, AC single-phase and three-phase supplies.
Watts to amps chart
Power factor 1 (DC, heaters, kettles). Motors and other loads draw more.
| Watts | 12 V | 120 V | 230 V | 240 V |
|---|---|---|---|---|
| 100 W | 8.33 A | 0.83 A | 0.43 A | 0.42 A |
| 500 W | 41.67 A | 4.17 A | 2.17 A | 2.08 A |
| 1,000 W | 83.33 A | 8.33 A | 4.35 A | 4.17 A |
| 1,500 W | 125 A | 12.5 A | 6.52 A | 6.25 A |
| 2,000 W | 166.67 A | 16.67 A | 8.7 A | 8.33 A |
| 3,000 W | 250 A | 25 A | 13.04 A | 12.5 A |
| 5,000 W | 416.67 A | 41.67 A | 21.74 A | 20.83 A |
Need the reverse? Use the amps to watts calculator.
Questions
How do I convert watts to amps?
For DC, divide watts by volts: 1,200 W at 120 V is 10 A. For AC single-phase, divide by the power factor times the volts. For three-phase, divide by √3 × power factor × the line-to-line voltage.
How many amps is 1,500 watts?
At 120 V it is 12.5 A; at 230 V about 6.5 A; at 240 V 6.25 A (DC or a power factor of 1).
What is power factor?
For AC equipment, power factor (0 to 1) describes how much of the current does useful work. Heaters and kettles are close to 1; motors are often 0.8–0.9. If you don't know it, 1 gives the minimum current.
What voltage should I use?
In the US and Canada household voltage is 120 V (240 V for large appliances). In the UK and most of Europe it is 230 V. Check the rating plate on the appliance.
Can I use this to size a fuse, breaker or cable?
No. This converts between watts and amps only. Sizing circuits depends on wiring regulations, cable type, length and installation, so ask a qualified electrician.
Why does three-phase need √3?
In a balanced three-phase supply, total power is √3 × line voltage × current × power factor, so the √3 (about 1.732) appears when converting.
For conversion only, not for sizing cables, fuses or breakers. Electrical installation work should follow your local wiring regulations.