How Many Amps Does a Space Heater Use?

A space heater uses about 12.5 running amps at 120 volts (roughly 1,500 watts). To get your unit's exact draw, divide the nameplate watts by 120: amps = watts / volts. A 1,500 watt space heater draws exactly 12.5 amps, which is 83% of a 15A circuit, so it should be the only significant load on that circuit and never on an extension cord. Two 1,500W heaters cannot share one 15A or 20A circuit. Fixed electric heat is a continuous load sized at 125% (NEC 424.3(B)); a portable heater follows the 80% rule of thumb.

A space heater belongs on a dedicated 15A / 120V circuit (NEC 210.23(A), 424.3(B)). At 12.5 running amps it stays under the 80% continuous limit of that breaker, with headroom for the startup surge. Do not put it on a shared circuit with other large loads.

Divide the wattage on the nameplate by the voltage: amps = watts / volts. A space heater at about 1,500 watts on 120V works out to 1,500 / 120 = 12.5 amps. The nameplate always governs over a typical value.

Same answer: electric space heater is another name for a space heater. It draws about 12.5 amps at 120V on a dedicated 15A circuit. A 1,500 watt space heater draws exactly 12.5 amps, which is 83% of a 15A circuit, so it should be the only significant load on that circuit and never on an extension cord. Two 1,500W heaters cannot share one 15A or 20A circuit. Fixed electric heat is a continuous load sized at 125% (NEC 424.3(B)); a portable heater follows the 80% rule of thumb.