15,000 Watts to Amps — How Many Amps Is 15,000 Watts?
15,000 Watts equals 125.00 amps at 120V or 62.50 amps at 240V. Common 15000W devices: Electric furnace, tankless water heater.
15,000 Watts Amps at Every Voltage
| Voltage | Single Phase | Three Phase |
|---|---|---|
| 120V | 125.00A | 72.17A |
| 208V | 72.12A | 41.64A |
| 240V | 62.50A | 36.09A |
| 277V | 54.15A | 31.27A |
| 480V | 31.25A | 18.04A |
The Formula
Single Phase: Amps = Watts ÷ Volts. For 15,000 Watts at 120V: 15000 ÷ 120 = 125.00A.
Three Phase: Amps = Watts ÷ (Volts × 1.732). For 15,000 Watts at 240V 3-phase: 15000 ÷ (240 × 1.732) = 36.09A.
With power factor: Amps = Watts ÷ (Volts × PF). A PF of 0.8 increases the current draw by 25%.
Wire and Breaker for 15,000 Watts at 120V
At 120V, 15,000 Watts draws 125.0A. Recommended: 4 AWG copper wire with a 70A breaker per NEC 310.16. For continuous loads (3+ hours), apply 125% rule. Use our Wire Size Calculator for exact sizing.
Common 15000W Devices
Electric furnace, tankless water heater. Always check the device nameplate for exact wattage — rated watts may differ from actual consumption.
Disclaimer: Calculations are for reference. Verify with device nameplate. Consult a licensed electrician for installations.