For air fryer vs microwave energy usage, the microwave is usually the cheaper choice for reheating a single portion, while the air fryer is often better when you want a crisp, browned finish. A microwave can heat suitable food in minutes; an air fryer heats and circulates hot air, often taking longer. The most economical appliance therefore depends on what you’re cooking, how much food you have and the texture you want.
UK electricity prices make every kilowatt-hour worth considering. But looking at watts alone is misleading: a microwave may have a fairly high input-power rating while using relatively little electricity because it runs for a short time. Below, we’ll compare example costs, cooking results and the meals best suited to each appliance.
The Quick Answer: Which Uses Less Electricity?
For a small portion of leftovers, soup or ready meal, the microwave usually uses less electricity. For chips, roast potatoes or breaded foods where crispness matters, an air fryer can be more effective, even if it costs more per session. Neither is automatically better for every meal.
| Cooking Task | Usually More Practical | Main Reason |
|---|---|---|
| Reheat soup or curry | Microwave | Fast heating of moist food |
| Reheat roast potatoes | Air fryer | Helps restore crispness |
| Heat a single ready meal | Microwave | Short programme |
| Cook crispy chicken pieces | Air fryer | Circulating hot air browns surfaces |
| Warm a mug of milk | Microwave | Suitable container and quick heating |
| Prepare a large family meal | Depends on quantity | Multiple batches may be necessary |
How Air Fryers and Microwaves Use Energy
A microwave uses electromagnetic energy to heat food, with heating patterns affected by the food’s composition, shape and size. It generally does not need to preheat a cavity in the way a hot-air cooking appliance does. This makes it particularly convenient for moist foods and reheating.
An air fryer is effectively a compact fan-assisted oven. A heating element warms the air and a fan moves that heat around the food. Its smaller chamber can be efficient compared with a large oven, but it must still heat the food and surrounding air. Some air-fryer meals require much longer than microwave reheating.
Important distinction: a microwave’s quoted 800W or 900W often refers to microwave cooking output, not electrical input. Its actual input-power rating may be higher. Check the rating label or manual before calculating costs.
Air Fryer vs Microwave UK: Realistic Cooking Costs
For October to December 2026, Ofgem lists an average electricity unit rate of 26.32p per kWh for Great Britain households on capped variable tariffs paying by direct debit. Your tariff and region may differ, and the daily standing charge is not an additional cost caused by cooking one meal.
Consider the following illustrative constant-power examples. They are arithmetic demonstrations, not measured results for specific models. Appliances can cycle heating elements or vary their power consumption.
| Example Session | Energy Calculation | Cost at 26.32p/kWh |
|---|---|---|
| Microwave: 1.2kW for 5 minutes | 0.10kWh | 2.6p |
| Microwave: 1.2kW for 8 minutes | 0.16kWh | 4.2p |
| Air fryer: 1.5kW for 15 minutes | 0.375kWh | 9.9p |
| Air fryer: 1.5kW for 20 minutes | 0.50kWh | 13.2p |
The Energy Saving Trust’s October 2026 UK cooking comparison offers a separate real-food example: approximately 4p to heat a 400g ready-made lasagne in a microwave in Great Britain. Its air-fryer example concerns a different food, so those headline figures should not be mistaken for a like-for-like microwave versus air-fryer experiment.
Which Consumes More Electricity: Air Fryer or Microwave?
For quick reheating, an air fryer will often consume more electricity because the cooking session is longer. A microwave might heat a portion in just a few minutes, whereas restoring a crisp exterior in an air fryer can take considerably longer. But absolute electricity use depends on the actual power drawn and duration.
A 1,500W air fryer is not necessarily drawing 1,500W every second; its heater may cycle. Likewise, an 800W microwave output label should not be substituted for its electrical input. The most accurate comparison is to measure both devices completing the same appropriate dish with an electricity monitor.
Is an Air Fryer Better Than a Microwave for Reheating Food?
It is better for some foods, not all. If texture matters most, the air fryer often has an advantage. Roast potatoes, certain pastries and foods with a crisp coating may emerge more appealing after hot-air reheating. The microwave tends to soften surfaces but is often quicker and cheaper.
For soup, rice dishes with sauce, curry and similar moist meals, a microwave is usually the more convenient option. Use a suitable microwave-safe container, cover or stir as directed and follow the food’s instructions. The Food Standards Agency’s food safety advice says leftovers should be reheated until steaming hot throughout, and microwaved food should be stirred or turned where needed to avoid cold spots.
Whichever appliance you choose, safe reheating is more important than saving a penny. Follow appropriate storage instructions and reheat leftovers only once, in line with UK food-safety guidance.
When an Air Fryer Makes More Sense
An air fryer is useful when the cooking result requires circulating hot air rather than simply heating food. Chips, roasted vegetables and crispy chicken pieces are obvious examples. A microwave may cook some ingredients, but it generally cannot reproduce the same browned, crisp finish.
The air fryer can also be practical for one or two portions instead of heating a large oven. Our guide to air fryer size for two people explains why basket dimensions and food quantities matter. If you need several successive batches, total energy use and time can rise.
When a Microwave Is the Better Choice
A microwave is particularly useful for warming drinks, reheating cooked vegetables, soups, sauces and portioned meals. It can also be an economical way to reheat food prepared earlier in a large batch. Some models offer grilling or convection functions, but an ordinary microwave’s greatest advantage remains speed for appropriate foods.
The Energy Saving Trust recommends batch cooking when appropriate and reheating portions as needed in the microwave. This can combine the convenience of preparing several meals at once with low-energy, short reheating sessions during the week.
Does Food Quantity Change the Comparison?
Absolutely. A small microwaveable meal may need only one short cycle. An air fryer loaded with several portions may take longer, and overcrowding can reduce browning. Cooking additional rounds makes the cost-per-meal comparison less favourable.
However, cooking an ingredient that is poorly suited to microwaving isn’t necessarily a meaningful contest. To be fair, compare the same food, portion count and acceptable finished result. An air-fried crispy potato wedge and a microwaved soft potato wedge are not necessarily equivalent dishes.
What About Buying Costs and Everyday Convenience?
If you own a microwave already, buying an air fryer purely to cut the electricity used when reheating leftovers is unlikely to make financial sense. The microwave often performs that task more cheaply. An air fryer might still be worthwhile for meals you currently cook in an oven or for food where browned texture makes a difference.
Our related article Are Air Fryers Worth Buying UK? considers appliance ownership more broadly, including convenience and the danger of spending on features you rarely use. Energy cost is one part of value, not the entire decision.
How to Compare Your Own Appliances
- Check your electricity tariff’s pence per kWh.
- Find the appliance’s electrical input rating, not microwave cooking output.
- Record the time taken to prepare a suitable comparable portion.
- Use a compatible energy monitor if you want measured kWh rather than an estimate.
- Include preheating and extra batches in total consumption.
- Judge whether the finished food has the texture and temperature you want.
For an estimate, divide electrical input watts by 1,000, multiply by running hours and then multiply by your tariff. For a more reliable result, measure a normal cooking cycle. Repeating a test with comparable food quantities can reduce the effect of a particularly unusual session.
Frequently Asked Questions
Is a Microwave Cheaper Than an Air Fryer for Leftovers?
Usually, especially for a single portion of moist food. Microwaves often heat it in a few minutes, while the air fryer may run longer to achieve a crisp finish.
Which Is Better for Reheating Pizza?
An air fryer may give a firmer crust, while a microwave is generally quicker and can leave the base softer. Check the appliance instructions and food thickness to ensure thorough reheating.
Can an Air Fryer Replace a Microwave?
It can do some reheating jobs, but it is generally less convenient for soup, drinks and many saucy leftovers. Households that regularly microwave food may find both appliances useful for different purposes.
Does a Microwave’s 900W Rating Mean It Uses Less Than a 1,500W Air Fryer?
Not necessarily. A microwave’s headline 900W may describe cooking output, while its electrical input can be higher. Total kWh depends on input power and time, not one headline number.
Final Verdict: Air Fryer vs Microwave Energy Usage
For air fryer vs microwave energy usage, the microwave generally wins for quick reheating and many small moist meals. The air fryer becomes more attractive when crispness, browning or oven-style cooking is the main goal. The appliance with the lowest energy use is not necessarily the one that delivers the result you want.
The best way to judge air fryer vs microwave energy usage in your kitchen is to compare equivalent finished portions, record kWh where possible and use your own tariff. For reheating curry, start with the microwave; for restoring crispy roast potatoes, the air fryer may be worth the extra pennies.