How Many Amps Does an Appliance Use?

A household refrigerator uses about 6 running amps at 120 volts (roughly 700 watts), but the compressor motor can surge to 12 to 15 amps for a moment at startup. That is why a fridge should be on its own 15A or 20A circuit and not share with other large loads. Divide the nameplate watts by 120 to get your unit's exact running amps.

An electric dryer draws about 21 to 24 amps at 240 volts (around 5,000 watts) and is installed on a dedicated 30A / 240V circuit with 10 AWG copper wire. A gas dryer only uses its 120V controls, about 5 amps. Always size to the nameplate; a few large dryers need a 40A circuit.

A full-size microwave uses about 10 amps at 120 volts (roughly 1,200 watts of input power, which is more than its cooking-power rating). A built-in or over-the-range microwave should be on its own dedicated 20A circuit. Countertop units can run on a 15A or 20A small-appliance circuit if nothing large shares it.

A dishwasher uses about 10 to 12 amps at 120 volts (around 1,400 watts with the heating element on). It belongs on a dedicated 15A or 20A circuit, GFCI protected under the current NEC. The heating element for dry cycles is what pushes the current toward the top of that range.

A window air conditioner uses about 5 to 13 amps at 120 volts depending on size: a small 5,000 BTU unit is around 5 amps, and a large 12,000 BTU unit can reach 12 to 13 amps, with a brief compressor surge above that. Large units may need a dedicated 20A circuit or a 240V outlet; check the unit's plug type and nameplate.

Divide the appliance's wattage by its voltage: amps = watts / volts. A 1,500 watt space heater on 120V draws 1,500 / 120 = 12.5 amps. For a motor load, add a startup surge of several times that for a fraction of a second. Keep the continuous running load under 80% of the circuit breaker, and always defer to the nameplate rating.