How many watts does a microwave use?

By Tom Calder · Figures checked 4 November 2026 · Costs at 26.32p per kWh (Ofgem cap, 1 October to 31 December 2026)

In short

An 800W or 900W microwave draws more than its label: 1,250W to 1,450W from the socket. Five minutes uses about 0.1 kWh, roughly 3p at 26.32p per kWh.

A kettle coming to the boil beside a microwave and slow cooker in a warmly lit kitchen on a rainy evening

The numbers

Running watts: 1,250W to 1,450W
Amps at 230V (most): 6.3A
Energy for 5 minutes: 0.1 to 0.12 kWh; Draw × time: 1,250W to 1,450W for 5 minutes, an example length.
Cost for 5 minutes: 3p
Cost per hour at full power: 33p to 38p
On a 1kWh power station: 6.4 to 7.7 five-minute heats
On a 2kWh power station: 13 to 15 five-minute heats

Costs use 26.32p per kWh, the Ofgem price cap's average Direct Debit electricity unit rate for 1 October to 31 December 2026. Your own rate is on your bill; on a fixed or time-of-use tariff it will differ.

How it’s used, and what that costs

The power printed on the door is the cooking output, not what the microwave draws. Panasonic’s 800W NN-E28JMM draws up to 1,250W and Sharp’s 800W R-272 draws 1,270W; Sharp’s 900W R-372 draws 1,450W. Microwaves run in short bursts, so although the draw is high, the energy per use is small.

The honest bit

For reheating a portion, a microwave is one of the cheapest ways to cook because it runs for minutes, not an hour. It is the draw, not the energy, that limits it on a power station.

In a power cut: how long a power station would run it

A 1kWh power station: 6.4 to 7.7 five-minute heats. A 2kWh power station: 13 to 15 five-minute heats. These use the same planning method as our power station pages: capacity × 90% usable depth × 85% inverter efficiency, divided by the load plus about 10W the unit uses itself (BLUETTI’s UK formula). Counts of uses leave out the unit’s own draw, so treat them as a little generous.

Output matters as much as capacity. The 7 units around 1kWh we list supply 1,500W to 2,000W continuously, and the 6 around 2kWh supply 2,200W to 3,000W, so check a unit’s rated output covers 1,450W before you rely on it.

A 600W-class power station cannot run one; a 1kWh unit with 1,500W or more of output can, for short bursts. See what size power station do I need.

To size one for everything you’d want to keep running, use the sizer on our power stations comparison.

Common questions

Why does my 800W microwave draw 1,250W?

Because 800W is the microwave energy delivered to the food, measured to the IEC 60705 standard. Converting mains power into microwaves loses some as heat, so the input is higher: Panasonic gives 1,250W for its 800W NN-E28JMM.