Watts to Amps Converter — Free Online Calculator
Convert watts to amps instantly. Works for single-phase and three-phase AC, plus DC circuits. Enter watts, voltage, and power factor.
How to Use This Calculator
Enter the power in watts, the voltage, and select DC, single-phase AC, or three-phase AC. For AC circuits, you can also enter the power factor (default 1.0 for resistive loads). The calculator converts watts to amps using the appropriate formula.
The Formula Explained
For DC: Amps = Watts / Volts. For single-phase AC: Amps = Watts / (Volts × Power Factor). For three-phase AC: Amps = Watts / (Volts × √3 × Power Factor). Power factor accounts for the phase difference between voltage and current in AC circuits — resistive loads like heaters have PF = 1, while motors typically have PF = 0.8-0.9.
Common Watts to Amps Conversions (120V, PF=1)
| Watts | Amps @ 120V | Amps @ 240V | Breaker Size |
|---|---|---|---|
| 500W | 4.17A | 2.08A | 15A |
| 1000W | 8.33A | 4.17A | 15A |
| 1500W | 12.50A | 6.25A | 15A |
| 2000W | 16.67A | 8.33A | 20A |
| 3000W | 25.00A | 12.50A | 30A |
| 5000W | 41.67A | 20.83A | 50A |
| 7500W | 62.50A | 31.25A | 70A |
| 10000W | 83.33A | 41.67A | 100A |