1 kW to Amps — How Many Amps Is 1 kW?
1 kW equals 4.17 amps at 240V (single phase) or 2.41 amps at 240V 3-phase. Common 1kW loads: Small space heater, microwave, window AC.
1 kW to Amps
4.17 A
at 240V single phase
1 kW Amps at Every Voltage
| Voltage | 1-Phase | 3-Phase |
|---|---|---|
| 120V | 8.33A | 4.81A |
| 208V | 4.81A | 2.78A |
| 240V | 4.17A | 2.41A |
| 277V | 3.61A | 2.08A |
| 480V | 2.08A | 1.20A |
The Formula
Single Phase: Amps = (kW × 1000) ÷ Volts. For 1 kW at 240V: (1 × 1000) ÷ 240 = 4.17A.
Three Phase: Amps = (kW × 1000) ÷ (Volts × 1.732). For 1 kW at 240V 3φ: (1 × 1000) ÷ (240 × 1.732) = 2.41A.
Wire and Breaker for 1 kW
At 240V single-phase (4.2A), recommended: 14 AWG copper with a 15A breaker. Use our Wire Size Calculator for exact sizing.
Disclaimer: Calculations for reference. Consult a licensed electrician.