How many amps is 1,500 watts?
Short answer: 1,500 watts draws 12.50 amps at 120 volts and 6.25 amps at 240 volts (amps = watts ÷ volts). From a 12 V battery through an inverter it is about 147 amps. At 120 V it needs a 20 A circuit if it runs for three hours or more.
1,500 watts to amps at every common voltage
| Voltage | Where you find it | Amps |
|---|---|---|
| 120 V | US household outlet | 12.5 A |
| 208 V | Three-phase building supply | 7.21 A |
| 240 V | US large-appliance circuit | 6.25 A |
| 12 V | Car or RV battery | 125.0 A |
| 24 V | 24 V battery bank | 62.5 A |
| 48 V | 48 V battery bank | 31.3 A |
amps = watts ÷ volts 1,500 W ÷ 120 V = 12.50 A 1,500 W ÷ 240 V = 6.25 A
Can a 1,500 W load go on a 15 or 20 amp circuit?
A breaker can carry its full rating, but NEC 210.20(A) limits a continuous load (three hours or more, like a heater left on overnight) to 80% of it.
| Circuit | Full rating (W) | Can it run 1,500 W? |
|---|---|---|
| 15 A, 120 V | 1,800 | Yes, but not for 3 h+ |
| 20 A, 120 V | 2,400 | Yes, even continuous |
| 15 A, 240 V | 3,600 | Yes, even continuous |
| 20 A, 240 V | 4,800 | Yes, even continuous |
| 30 A, 240 V | 7,200 | Yes, even continuous |
Remember that everything else on the same circuit counts. A 1,500 W heater on a bedroom circuit that also feeds a TV and a computer can trip the breaker even when the heater alone would fit.
What uses about 1,500 watts
- Space heaters: 1,500 W is the maximum for a US plug-in heater
- Electric kettles and toaster ovens
- Hair dryers on a medium setting (most are 1,500–1,875 W)
- Portable induction burners
Running 1,500 W on backup power
From a portable power station's AC outlets, counting 15% inverter loss, if the inverter is rated for at least 1,500 W:
| Power station | Runtime at 1,500 W |
|---|---|
| 1,024 Wh | 35 min |
| 2,048 Wh | 1.2 h |
| 3,600 Wh | 2.0 h |
On a generator, a resistive 1,500 W load needs about 1,900 running watts to keep the 20% margin; a motor load of the same running watts needs room for its starting surge too. Check your whole list in the generator size calculator.
What 1,500 watts costs to run
At the US average residential price of 18.19¢/kWh (EIA, January–July 2026), 1,500 W costs $0.27 per hour, or about $24.56 a month at three hours a day. State averages run from 12.36¢ to 46.28¢; use the appliance cost calculator with your state.