Air fryer vs oven vs slow cooker vs microwave: running costs at this winter's price cap

Under Ofgem's price cap for 1 October to 31 December 2026, electricity costs 26.32p a kWh and gas 7.97p a kWh on average for people paying by Direct Debit. The government has taken VAT off electricity bills from 1 October 2026 to 31 March 2027, while gas still carries 5% VAT. We've used those rates and real appliance power ratings to work out what each way of cooking costs.

At a glance

• Electric oven (2.4kW), one hour: up to 63p.
• Air fryer (2kW), 20 minutes: up to 18p.
• Slow cooker (200W), eight hours: up to 42p.
• Microwave, 10 minutes: about 5p.
• Gas hob burner (about 2kW), 30 minutes: about 8p.

How we worked it out

Running cost is power (kW) × hours × price per kWh. We used the power ratings on John Lewis product pages:

• Electric oven: Bosch Series 2 HHF113BR0B single oven, 2.40kW.
• Air fryer: Ninja AF140 Air Fryer Pro, 2000W, 4.7 litres, £89.99.
• Slow cooker: Russell Hobbs Chalkboard 3.5 litre, 200W, £29.99.
• Microwave: Panasonic NN-ST22 20 litre, 800W cooking power. A microwave draws more from the socket than its cooking power, so we've assumed 1.2kW.
• Gas hob: we've assumed a 2kW burner.

These are maximum figures. Ovens, air fryers and slow cookers switch their elements on and off once they're up to temperature, so they usually use less. Treat them as a ceiling, not an exact cost.

The costs in detail

• Electric oven: 2.4kW × 1 hour = 2.4kWh × 26.32p = up to 63.2p. Preheating adds to this.
• Air fryer: 2kW × 20 minutes = 0.67kWh = up to 17.5p. There's little or no preheating.
• Slow cooker: 0.2kW × 8 hours = 1.6kWh = up to 42.1p, for a whole stew.
• Microwave: 1.2kW × 10 minutes = 0.2kWh = about 5.3p.
• Gas hob: 2kW × 30 minutes = 1kWh × 7.97p = about 8p.

Your standing charges (54.83p a day for electricity and 29.68p for gas on average) are the same however you cook, so they don't change these comparisons. Rates vary by region and payment method.

Worked example: a family's week

Say you cook chicken and chips four nights a week. In the oven, at around 45 minutes and up to 1.8kWh each time, that's up to 7.2kWh, or about £1.90 a week. In an air fryer for 25 minutes, it's up to 0.83kWh each time, or about 3.3kWh a week, which is about 88p. That's up to £1.02 a week less, or about £8 over the eight weeks left of the current cap period.

There's a catch: a 4.7-litre air fryer won't fit a meal for four in one go, and two batches cancel out much of the saving. For a big roast, the oven is still the practical choice. Cooking several things in the oven at once helps.

What to do now

1. Check the power rating (W or kW) on the appliances you already have.
2. Use the smallest appliance that fits the meal: microwave for reheating, air fryer for small portions, oven for full trays.
3. Batch cook in the slow cooker or oven, then reheat portions in the microwave.
4. Put lids on pans on the hob, and match the pan to the ring.
5. Don't buy a new gadget just to save energy. At up to £1 a week, an £89.99 air fryer takes well over a year to pay for itself.

Questions

Why is there no VAT on electricity?

Ofgem says the government has removed VAT from electricity bills from 1 October 2026 to 31 March 2027. Gas bills still include 5% VAT.

Will the cap change in January?

Ofgem will announce the cap for 1 January to 31 March 2027 on 25 November 2026. Until then, we can't say whether rates will go up or down.

Is a slow cooker cheap to run?

Per hour, yes: up to about 5p. It runs for a long time, though, so a whole day costs up to about 42p, which is similar to some oven meals.

Ways to save

If you're buying, compare prices at Ninja, John Lewis, Currys and Robert Dyas, and check the power rating before you buy.

Rates and prices checked on 1 November 2026. Sources: Ofgem: price cap 1 October to 31 December 2026, Ofgem: summary of changes, John Lewis: Bosch HHF113BR0B, John Lewis: Ninja AF140, John Lewis: Russell Hobbs slow cooker, John Lewis: Panasonic microwave

Ad: affiliate links. The codes and deals below link to the stores, and we may earn a commission if you buy, at no cost to you. How we make money.