How Many Amps Does a Microwave Use?

A microwave uses about 10 running amps at 120 volts (roughly 1,200 watts). To get your unit's exact draw, divide the nameplate watts by 120: amps = watts / volts. A microwave's advertised rating (700-1200 W) is its cooking (output) power, not the power it pulls from the wall: input is roughly 1.4x the cooking rating. This page's 1,200 W figure is the input (draw) wattage, about 10 amps; a microwave sold as '1000 W' refers to cooking power, which needs about 1,450 W input and draws about 12 amps. A built-in or over-the-range unit should be on its own dedicated 20A circuit; a countertop unit can share a 20A small-appliance circuit if nothing large is on it.

A microwave belongs on a dedicated 20A / 120V circuit (NEC 210.8(A), 210.23(B)). At 10 running amps it stays within the 80% continuous limit of that breaker. 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 microwave at about 1,200 watts on 120V works out to 1,200 / 120 = 10 amps. The nameplate always governs over a typical value.

Yes. A 700 W (input ~1000 W) draws about 8.3 amps, while a 1200 W (input ~1700 W) draws about 14.2 amps. See the table above for the range. The rating on the nameplate is the number to size the circuit to.

Same answer: built-in microwave is another name for a microwave. It draws about 10 amps at 120V on a dedicated 20A circuit. A microwave's advertised rating (700-1200 W) is its cooking (output) power, not the power it pulls from the wall: input is roughly 1.4x the cooking rating. This page's 1,200 W figure is the input (draw) wattage, about 10 amps; a microwave sold as '1000 W' refers to cooking power, which needs about 1,450 W input and draws about 12 amps. A built-in or over-the-range unit should be on its own dedicated 20A circuit; a countertop unit can share a 20A small-appliance circuit if nothing large is on it.