FieldnotesSIGN IN
vouchernaut
Stores & offersShop

ENERGY · RUNNING COSTS

What a microwave costs to run

On the price cap from 1 October to 31 December 2026, a 1.27 kW microwave at full power costs 2.8p for 5 minutes, in Great Britain on average and paying by Direct Debit. Put in your own model and region below.

What you know about it

Use the input power, not the headline figure. The advertised watts (800 W, say) are the cooking power; what it draws from the socket is listed as connected load, total load rating or power consumption, and is higher: John Lewis's 800 W JLSMWO08 draws 1.27 kW.

Each time it runs

Every day is 7; once a fortnight is 0.5.

How you pay

Each time it runs

2.8p

At 26.32p a kWh: the cap's Great Britain average on Direct Debit, 1 October 2026 to 31 December 2026.

An hour at full power
33.4p
A week
19.5p
A month
84.7p
A year
£10.17

The working

  1. 1.27 kW for 5 minutes uses 0.106 kWh at full power.
  2. 0.106 kWh × 26.32p a kWh (Great Britain average, Direct Debit, VAT included) = 2.8p each time.
  3. 7 times a week is 19.5p; × 52.14 weeks = £10.17 a year, or 84.7p a month.

The standing charge (54.83p a day here) isn't in these figures: you pay it whatever you run. On Economy 7 or another time-of-use tariff, the cost depends on when it runs and your supplier's rates.

Real models

Ratings from each maker's or retailer's page. Great Britain average, Direct Debit.

ModelRatingAn hour
Bosch FFL023MS2B Series 2 20L solo microwave, 800 W output1.27 kW33.4p
John Lewis JLSMWO08 20L microwave, 800 W output1.27 kW33.4p
Hisense H25MOBS7HUK 25L solo microwave, 900 W output1.45 kW38.2p

Where you live

A 1.27 kW microwave at full power, on Direct Debit. The Great Britain average is 27.80p a kWh paying on receipt of a bill, and 25.52p on prepayment.

RegionA kWhEach timeA year
Great Britain average26.32p2.8p£10.17
Eastern England26.61p2.8p£10.28
East Midlands25.36p2.7p£9.79
London26.60p2.8p£10.27
Merseyside and North Wales27.86p2.9p£10.76
West Midlands25.60p2.7p£9.89
North East England25.46p2.7p£9.83
North West England26.49p2.8p£10.23
Southern England26.47p2.8p£10.22
South East England26.88p2.8p£10.38
South Wales26.55p2.8p£10.26
South West England26.58p2.8p£10.27
Yorkshire25.60p2.7p£9.89
South Scotland26.11p2.8p£10.08
North Scotland26.35p2.8p£10.18

A year is 5 minutes a day, every day: my assumption, so put in your own use above.

Air fryer, oven or microwave

The same dishes, measured. Great Britain average, Direct Debit.

DishAir fryerElectric ovenMicrowave
Jacket potato, about 200 g10.3p: 48 min, 0.392 kWh28.5p: 68 min, 1.084 kWh3.9p: 8 min, 0.149 kWh

Which? cooked each dish in a Morphy Richards Health Fryer 480003 air fryer and a Bosch Serie 2 HHF113BR0B built-in oven, measuring the energy in its lab, any preheating included. The microwave's jacket potato is from its microwave buying guide. Each cost is the energy it measured at 26.32p a kWh. Cooking in batches can change the answer: a full oven cooks more at once. (Which?: air fryer vs oven, energy use and cooking results compared (16 October 2026); Which?: how to buy the best microwave (1 October 2026))

What it uses

Use the input power, not the headline figure. The advertised watts (800 W, say) are the cooking power; what it draws from the socket is listed as connected load, total load rating or power consumption, and is higher: John Lewis's 800 W JLSMWO08 draws 1.27 kW.

Does it always use this much? At full power, yes. At lower power levels a conventional (non-inverter) microwave repeatedly switches its power off and on to hold the level, so it averages less than its rated input.

Spending less

Questions

How much does a microwave cost to run?

A 1.27 kW microwave at full power costs 2.8p for 5 minutes at the price cap's 26.32p a kWh (Great Britain average, Direct Debit, from 1 October to 31 December 2026). For 5 minutes a day, every day, that's £10.17 a year. The calculator above takes your own model, use, region and how you pay.

Does a microwave use electricity when not in use?

A little, for the clock and controls. Panasonic lists 0.68 W in standby for its NN-E28JB compact microwave, and Energy Saving Trust counts microwaves among the appliances worth switching off at the plug.

Does an 800W microwave use 800 watts?

No, it uses more. The 800 W is the cooking power; the Bosch FFL023MS2B, an 800 W model, lists a connected load of 1270 W from the socket.

Is a microwave cheaper to run than an oven?

Usually, for reheating and quick cooking. Energy Saving Trust says a microwave heats the food directly rather than the air around it, so its cost per use is likely to be lower than many other cooking appliances.

Sources

Other appliances

Compare energy tariffs to see what a year would cost you on each.