Energy and running costs
The Cost of Reheating Leftovers: Air Fryer vs Microwave vs Oven
Published by the RecipeAirFryer editorial team · How we source times · Updated
Reheating a portion of leftovers costs an average of 4.7p in an air fryer and 18.0p in an electric oven at the UK price cap, across 10 common leftovers. Two minutes in a microwave costs 1.1p. The microwave is the cheapest by a wide margin, and the air fryer is the cheapest way to get a crisp result.
Key findings
- At US prices the averages are 3.3¢ for the air fryer and 12.5¢ for the oven, with two microwave minutes at 0.7¢.
- The oven costs about 3.9 times as much as the air fryer for a reheat, because the oven's preheat is longer than the reheat itself.
- Per minute of running, the microwave costs 0.5p, the air fryer 0.7p and the oven 1.1p.
- All of these are pennies. Texture is a better reason to choose than cost.
- Microwave, 2 minutes1.1p
- Air fryer, average of 10 leftovers4.7p
- Oven, average of 10 leftovers18.0p
Cost per minute of running
| Appliance | UK | US |
|---|---|---|
| Microwave (1,200 W at the wall) | 0.5p | 0.4¢ |
| Air fryer (1,500 W) | 0.7p | 0.5¢ |
| Oven (2,400 W) | 1.1p | 0.7¢ |
Air fryer and oven cost for 10 leftovers
| Leftover | Temperature | Time | Air fryer (UK) | Oven (UK) | Air fryer (US) | Oven (US) |
|---|---|---|---|---|---|---|
| Pizza | 160°C / 320°F | 3-5 min | 4.6p | 17.9p | 3.2¢ | 12.5¢ |
| Fries (Chips) | 180°C / 350°F | 3-5 min | 4.6p | 17.9p | 3.2¢ | 12.5¢ |
| Fried Chicken | 160°C / 320°F | 4-6 min | 5.3p | 19.2p | 3.7¢ | 13.4¢ |
| Cooked Chicken | 160°C / 320°F | 3-5 min | 4.6p | 17.9p | 3.2¢ | 12.5¢ |
| Burger | 160°C / 320°F | 3-4 min | 4.3p | 17.2p | 3.0¢ | 12.0¢ |
| Steak | 160°C / 320°F | 3-5 min | 4.6p | 17.9p | 3.2¢ | 12.5¢ |
| Chicken Nuggets | 180°C / 350°F | 3-4 min | 4.3p | 17.2p | 3.0¢ | 12.0¢ |
| Chips (Fries) | 180°C / 350°F | 3-5 min | 4.6p | 17.9p | 3.2¢ | 12.5¢ |
| Spring Rolls | 170°C / 340°F | 3-5 min | 4.6p | 17.9p | 3.2¢ | 12.5¢ |
| Roast Potatoes | 180°C / 350°F | 4-6 min | 5.3p | 19.2p | 3.7¢ | 13.4¢ |
We do not hold microwave times for these foods, so the microwave is shown as a flat two minutes for reference instead of a per-food figure.
How these figures were worked out
Energy is calculated, not metered: rated wattage multiplied by minutes of use. The air fryer is taken as 1,500 W with a 3-minute preheat. The oven is taken as 2,400 W with a 12-minute preheat. These are the default figures in our running cost calculator.
Air fryer minutes come from the recipe page. Oven minutes are the air fryer minutes divided by 0.8, which is the site's standard conversion (an air fryer takes about 80% of the oven time).
Prices are 26.32p per kWh (Ofgem price cap, October to December 2026) and 18.31¢ per kWh (EIA U.S. residential average, July 2026). Standing charges and taxes other than those already in the unit rate are left out, because they do not change with how you cook.
Both appliances switch their element off and on once they reach temperature, so every figure here is an upper limit. The gap between the two is a fair guide; the absolute numbers on your bill will be lower. Check the rating plate on your own appliances and your own tariff, then use the calculator for a figure that fits your kitchen.
The microwave is taken as drawing 1,200 W at the wall, which is typical for a model rated at about 800 W of cooking power. Check the rating plate on yours. Air fryer minutes are the midpoint of the range on each reheat page.
Sources
- Ofgem energy price cap, 1 October to 31 December 2026 (26.32p per kWh, GB average, Direct Debit)
- U.S. Energy Information Administration, Electric Power Monthly Table 5.6.A (18.31 cents per kWh, U.S. residential average, July 2026)
You may quote these figures with a link to this page. If you spot an error, tell us through the contact page and we will correct it.
Frequently Asked Questions
What is the cheapest way to reheat food?
A microwave. Two minutes costs about 1.1p or 0.7¢, against an average of 4.7p for an air fryer reheat including preheat.
Is it cheaper to reheat in an air fryer or an oven?
An air fryer. The average reheat costs 4.7p against 18.0p in an oven at the UK price cap, because the oven has to preheat for longer than the food takes to warm.
Why reheat in an air fryer if the microwave is cheaper?
Texture. Pizza, chips and anything fried or breaded go soft in a microwave and crisp again in an air fryer. The extra cost is a few pence.