Show the formula and working
This air fryer conversion calculator turns an oven recipe or ready meal instruction into an air fryer temperature and cooking time, or an air fryer recipe back into oven settings, for home cooks in the UK, Ireland and Europe. It accepts °C, °F or gas mark, and lets you set the temperature drop and time cut yourself, because no single rule fits every food and model.
Quick answer: A common air fryer conversion calculator rule is to lower the oven temperature by 20 °C and cut the cooking time by about 20%. An oven recipe of 200 °C for 30 minutes becomes 180 °C for 24 minutes in an air fryer. Shake or turn the food halfway and check it is steaming hot throughout.
What Is an Air Fryer Conversion Calculator?
An air fryer conversion calculator is a tool that estimates air fryer settings from oven instructions by applying a temperature drop and a percentage time reduction. In plain words: air fryer temperature equals oven temperature minus the drop, and air fryer time equals oven time multiplied by one minus the time reduction. Going the other way, it adds the drop back and divides the time by the same factor.
Air fryers are small fan ovens. The food sits close to the heating element in a strong flow of hot air, so it browns and cooks faster than in a large oven. Ninja’s UK guide says air fryers cut cooking time by about 20% on average, and much more for some foods in some models. That is why the 20 °C and 20% figures here are editable starting points rather than fixed rules.
How Do You Use the Air Fryer Conversion Calculator?
- Choose the Direction: “Oven recipe to air fryer” or “Air fryer recipe to oven”.
- Set the Temperature unit to °C, °F or Gas mark, matching the recipe or pack.
- Enter the Recipe temperature and the Recipe cooking time in minutes.
- Leave the Temperature drop at 20 °C for a conventional oven recipe, or lower it if the recipe already gives a fan oven temperature.
- Leave the Time reduction at 20%, or adjust it once you know how your own air fryer behaves.
- Read the setting, the Fahrenheit figure and the halfway check time, then open “Show the formula and working” to see each step.
How Do You Convert Oven Temperature to Air Fryer?
Lower a conventional oven temperature by about 20 °C (25 °F) for the air fryer: 200 °C in the oven becomes about 180 °C. If the recipe gives a fan oven temperature, the drop is usually smaller, because a fan oven already runs cooler than a conventional one for the same result. For gas mark recipes, the calculator first changes the mark to its usual °C value, so gas mark 6 counts as 200 °C. Most air fryer dials move in 5 °C or 10 °C steps, so results are rounded to the nearest 5 °C.
How Much Shorter Is Air Fryer Cooking Time?
Air fryer cooking is usually about 20% shorter than oven cooking, so 30 minutes in the oven becomes about 24 minutes. Thin, small or frozen foods such as chips and nuggets often finish sooner, while dense foods such as a whole chicken or thick joints may need close to the full oven time. A packed basket also slows cooking, so cook in a single layer and shake or turn the food halfway.
How Do You Know Air Fried Food Is Safe to Eat?
Food is safe when it is steaming hot all the way through, and the Food Standards Agency says the middle should reach 70 °C for 2 minutes. Use a clean food thermometer in the thickest part to check. For chicken and pork, there should be no pink meat in the centre and the juices should run clear, and burgers should not be served pink at home. A converted time is only an estimate, so always check before serving.
Oven to Air Fryer Temperature Chart
| Gas mark | Oven °C | Oven °F | Air fryer °C (20 °C lower) |
|---|---|---|---|
| 3 | 170 °C | 325 °F | 150 °C |
| 4 | 180 °C | 350 °F | 160 °C |
| 5 | 190 °C | 375 °F | 170 °C |
| 6 | 200 °C | 400 °F | 180 °C |
| 7 | 220 °C | 425 °F | 200 °C |
| 8 | 230 °C | 450 °F | 210 °C |
Gas mark values follow the standard table on Wikipedia’s gas mark page. At a 20% time cut, 20 minutes becomes 16, 45 minutes becomes 36 and 60 minutes becomes 48.
Worked Example: Frozen Chicken Kievs
Example: a pack of frozen chicken kievs says 200 °C for 30 minutes in a conventional oven. Keep the Direction on “Oven recipe to air fryer”, the Temperature unit on °C, enter 200 and 30, and leave the Temperature drop at 20 and the Time reduction at 20. The calculator works out 200 minus 20 = 180 °C and 30 x 0.8 = 24 minutes, so it shows 180 °C for 24 min, with a shake or check at 12 minutes. At 24 minutes, push a food thermometer into the thickest kiev and check it is steaming hot in the middle before serving.
Air fryers often cost less to run than heating a full oven for a small meal. To compare the two with your own tariff, use the electricity cost calculator, or browse our energy bill calculators.
Air Fryer Conversion Calculator FAQs
What is 180 °C in an air fryer?
An oven recipe at 180 °C converts to about 160 °C in an air fryer using the common 20 °C drop. If a recipe already says 180 °C for an air fryer, use it as written, because air fryer recipes are already adjusted.
Do I need to preheat my air fryer?
Follow your model’s manual. Some air fryers ask for a short preheat of a few minutes and some do not need one. If you skip preheating, the first minutes are cooler, so check the food at the end of the converted time and add a few minutes if needed.
Can I use oven chip instructions in an air fryer?
Yes. Lower the temperature by about 20 °C, cut the time by about 20%, spread the chips in one layer and shake the basket halfway. Many frozen food packs now print air fryer instructions too, and those should come first when they are given.
How do I convert an air fryer recipe to the oven?
Set Direction to “Air fryer recipe to oven”. The calculator adds the temperature drop back and divides the time by one minus the time reduction, so 180 °C for 24 minutes becomes 200 °C for 30 minutes, or gas mark 6.
Why is my air fryer food not cooked in the converted time?
The basket may be too full, the food may be thicker than usual, or your model may run cooler. Cook in smaller batches, turn food halfway and add time in short steps until it is steaming hot throughout.
Is the 20 °C rule the same for fan ovens?
No. The 20 °C drop is a rule of thumb for conventional oven temperatures. Fan oven temperatures are already lower, so many cooks use a smaller drop or none at all. Set the Temperature drop field to match the recipe you start from.
Checked October 2026. Sources: Cooking your food (Food Standards Agency, gov.uk), Air fryer cooking time guide (Ninja Kitchen UK), Gas mark (Wikipedia).