The key numbers

ApplianceWattage20-min cook at 24.5p/kWh
Electric oven (standard)2,000 - 2,500W16 - 20p + preheating
Oven preheating (15 min)2,200W13p extra
Air fryer (medium, 4L)1,200 - 1,600W10 - 13p
Air fryer (large, 7L+)1,700 - 2,200W14 - 18p

The three reasons an air fryer wins on electricity:

  1. No preheating: reaches cooking temperature in 1 - 3 minutes vs 10 - 20 minutes for an oven (that's 0.4 - 0.7kWh before your food is even in)
  2. Smaller space: heats less air volume, needs less energy to maintain temperature
  3. Faster cooking: typically 20 - 30% quicker, reducing total run time

Real-world cost comparison per meal

MealOven total costAir fryer costSaving
Chips (25 min)29p (40 min inc. preheat)6p (18 min)23p
Chicken breast29p (40 min inc. preheat)7p (20 min)22p
Sausages (6)25p (35 min inc. preheat)5p (15 min)20p
Roast potatoes44p (60 min inc. preheat)10p (30 min)34p
Small pizza18p (25 min inc. preheat)4p (12 min)14p
Fish fingers22p (30 min inc. preheat)4p (12 min)18p

For a household cooking 5 evenings a week with these types of meals, switching to an air fryer saves approximately £90 - 140/year.

The annual saving calculation

If you use your oven 5 nights a week for 20 - 30 minute weeknight meals:

Add the saving on your energy tariff - if you cook during cheap overnight Octopus Agile windows (unlikely for most people, but evening pre-peak at 5pm vs 7pm can cut cooking costs 30 - 50% further).

When the oven is still the better choice

The air fryer doesn't win for everything:

For everyday weeknight cooking for 1 - 4 people: air fryer wins every time.

Which air fryer uses the least electricity?

SizeBest forWattageCost per 20 min (at 5p/kWh overnight)
2 - 3L1 - 2 people900 - 1,200W1 - 2p
4 - 5L2 - 4 people1,200 - 1,600W2 - 3p
6 - 7L4 - 6 people1,600 - 2,000W3 - 4p

Want to cook even cheaper? Check when electricity is cheapest tonight

On Octopus Agile, cooking at 5pm (pre-peak) instead of 7pm (peak) can cut your cooking cost by 60%. See tonight's price for your region - free.

Check Tonight's Cheapest Times →

Is an air fryer worth buying to save electricity?

Yes, if you currently use the oven 4 - 7 nights a week for quick meals and are a 1 - 4 person household. Annual saving of £90 - 140 from a £30 - 80 appliance. Payback in 3 - 10 months.

Less rush if you already have a combi microwave, you mainly batch-cook, or your household of 6+ needs full oven capacity regularly.

Frequently asked questions

Does an air fryer use more electricity than a microwave?
Yes. A microwave uses 700 - 1,000W for 3 - 5 minutes to reheat food - making it the cheapest option for reheating leftovers. An air fryer takes 12 - 20 minutes. For reheating: microwave wins. For cooking crispy food from scratch: air fryer wins.
How much does it cost to run an air fryer for 20 minutes?
At the UK average 24.5p/kWh: approximately 8 - 13p depending on model. At overnight Octopus Agile rates (4 - 6p/kWh): approximately 2 - 4p per cook.
Can I cook everything in an air fryer?
Most everyday meals, yes. Exceptions: anything requiring boiling water, large items that need full oven space, and high-volume batch cooking. For 80% of weeknight meals for small households, an air fryer handles everything.