Current depends on both power and voltage: the same appliance draws half the current at 240 V that it does at 120 V.
How to use the Watts to Amps Calculator
- Power
- Voltage
- Circuit type
- Power factor
Results update as you type, and every field accepts the units shown in its menu.
How it works
Divide power by voltage, adjusted for power factor and for √3 in three-phase circuits.
Inputs explained
| Field | What to enter |
|---|---|
| Power | Units: W, kW, hp, mW |
| Voltage | Units: V, mV, kV |
| Circuit type | Choose one: DC or single-phase AC, Three-phase AC (line-to-line voltage) |
| Power factor | A number |
Example values
How the main result changes when Power changes and everything else stays at the example values above:
| Power (W) | Current (A) |
|---|---|
| 1,000 | 4.35 |
| 1,500 | 6.52 |
| 2,000 | 8.7 |
| 2,500 | 10.87 |
| 3,000 | 13.04 |
| 4,000 | 17.39 |
Formula
DC: I = P ÷ VSingle-phase: I = P ÷ (V × PF)Three-phase: I = P ÷ (√3 × V × PF)Worked example
Inputs — Power: 2,000 W; Voltage: 230 V; Circuit type: DC or single-phase AC; Power factor: 1.
Results — Current = 8.7 A.
Frequently asked questions
What breaker size do I need?
Choose one rated above the continuous current, following local electrical codes.
What power factor should I use?
1 for heaters; about 0.8–0.95 for motors.
What formula does the Watts to Amps Calculator use?
DC: I = P ÷ V.