Quick answer: A 2.5 kW electric oven costs up to about 66p an hour at full power under the Ofgem price cap of 26.32p per kWh. Because the thermostat cycles once the oven is hot, a typical meal with a 10-minute preheat and 40 minutes of cooking uses about 1.4 kWh, roughly 37p.
Ovens are among the most power-hungry appliances in a British kitchen, but they rarely run at full power for long. Here is what yours really costs and when another appliance is cheaper.
Electric oven running costs by power
| Oven power | UK per hour | UK per day | UK per month (20 hours) |
|---|---|---|---|
| 2,000 W | 53p | 53p | £10.53 |
| 2,500 W | 66p | 66p | £13.16 |
| 3,000 W | 79p | 79p | £15.79 |
Most single built-in fan ovens are rated between 2 and 3 kW; the rating is on the plate inside the door frame or in the manual. Cookers with two ovens and a hob draw more in total, but rarely all at once.
Why your oven costs less than the table
Once the oven reaches temperature, its thermostat switches the element on and off. Over a typical meal the element might run around 60% of the time after preheating:
- Preheat, 10 minutes at 2.5 kW: about 0.42 kWh.
- 40 minutes of cooking, element on about 60% of the time: about 1 kWh.
- Total: about 1.4 kWh, or 37p at the price cap.
Cheaper ways to cook
| Appliance | Energy per meal | UK per meal |
|---|---|---|
| Microwave, 6 minutes | 0.11 kWh | 2.9p |
| Air fryer, 20 minutes (1.5 kW) | 0.50 kWh | 13p |
| Slow cooker, 6 hours on low | 1.2 kWh | 32p |
| Electric oven, 10-minute preheat plus 40 minutes | 1.4 kWh | 37p |
Full comparison: air fryer vs oven vs microwave.
How to use the oven for less
- Fill it: cook several dishes or batch cook at the same time.
- Use the fan setting, which usually cooks at a lower temperature.
- Skip preheating for dishes that don’t need it, and switch off a few minutes early.
- Keep the door closed: every look lets heat escape.
Oven cost calculator
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Frequently asked questions
Is a gas oven cheaper to run?
Per kWh, gas is much cheaper under the price cap (7.97p for gas in October to December 2026), so a gas oven usually costs less to run even though it is less efficient.
How much does a Sunday roast cost to cook?
About 2 hours in a 2.5 kW oven running roughly 60% of the time after preheating uses around 3.4 kWh, about 89p.
A real example: a week of oven meals
A household that uses the oven for a typical meal five evenings a week (about 1.4 kWh each time, including preheating) uses 7.0 kWh a week, about £1.84, or around £95.80 a year.
Cooking two dishes at once, or batch-cooking for several days, is one of the simplest savings: the oven is already hot, so the second dish costs much less than cooking it separately.
Fan oven or conventional?
Fan ovens circulate hot air, so most recipes can be cooked about 20°C lower than in a conventional oven, and they heat up faster. That usually means less energy for the same meal. If your recipe gives a conventional temperature, reduce it by about 20°C when using the fan setting.
More questions readers ask
Should I preheat the oven?
For bread, cakes and pastry, yes. For many casseroles, roasts and reheated dishes, you can put the food in as the oven warms up and save the preheating time.
Does opening the oven door waste energy?
Yes. Each time you open the door the oven loses a lot of heat. Use the oven light and window to check food.
Sources
- Ofgem, Energy price cap.
- Our methodology.