Air fryer conversion

An oven recipe changes in two ways for an air fryer, and both rules come from the appliance makers rather than any law or standard. Instant Brands and COSORI UK put the air fryer 20 degrees lower than the oven temperature and shorten the cooking time by 20% to 25% for fresh food. The converter takes 20°C off the recipe's figure, rounds to the nearest 5°C and cuts the time by 20%, to the whole minute. With the starting values, 180°C for 25 minutes becomes 160°C for 20 minutes. COSORI UK's own example, 200°C for 30 minutes, comes out at 180°C for 24 minutes, the long end of its range. COSORI UK calls the rule a starting point, not a guarantee, so each of its figures is an input that an appliance's manual can replace.

No maker page read states the control's step, so 5°C steps are the converter's own choice, with a tie going to the cooler setting. Its results match the makers' printed pairs, as the cases under checked against known answers show.

Close to one, only smaller: the Energy Saving Trust says an air fryer works like a small conventional fan oven. A fan drives hot air around the food in a compact chamber.

A conventional oven heats from elements at the top and bottom with no fan. A fan oven adds one, and that hot air circulation is why British recipes print a lower fan figure. American recipes call it a convection oven.

Instant Brands still takes about 20°C off a fan recipe, and the converter's separate fan cut starts at 20 degrees. Moving a recipe between the two kinds of oven alone is a job for the oven setting converter.

180°C. BBC Good Food's conversion guide puts gas mark 6 at 200°C, and the makers' rule takes 20°C off.

A gas mark is a step on a gas oven's dial, not a unit. The marks rise in 25°F steps, from 225°F at mark ¼ to 475°F at mark 9.

Each mark is read as the tidy figure in degrees Celsius that the same guide prints, before the cut. Most gas cookers have no fan, so a mark counts as a conventional heat.

British recipes often print the heat three ways. Take breaded chicken strips printed as 220°C, 200°C fan or gas 7, baked for 20 minutes.

• Fan figure: 180°C for 16 minutes, turned after 8 minutes.
• Conventional figure: 200°C for the same 16 minutes.
• Gas 7, read as 220°C: 200°C.

The fan reading lands 20°C cooler because the makers take the same amount off either kind of recipe. Both follow the published rule. Either way the time is 4 minutes shorter than in the oven.

Some oven recipes ask for more heat than an air fryer gives. Tower lists its Vortx 9L, a dual-basket air fryer, at 50°C to 200°C, so the converter starts from that range.

A pizza at gas 9, 240°C, would need 220°C by the rule. The converter then shows 200°C, the highest setting, flags the shortfall and keeps the time at 10 minutes.

An oven-style air fryer, with a door and shelves, may reach a different top setting, and wattage and basket size vary between models too. The maximum is an input, taken from the manual.

Every mark from 1 to 7 drops by the same 20°C, while marks 8 and 9 stop at the top setting of 200°C. This conversion chart uses BBC Good Food's Celsius for each mark.

Times shrink by the same share at any heat. At the default 20%, a quarter of an hour becomes 12 minutes and an hour 48 minutes.

The way back adds the cut and lengthens the time. Going from air fryer to oven, 180°C for 20 minutes becomes 200°C for 25 minutes, or gas 6.

A fan oven gets the same 200°C, since the makers take the same 20°C off a fan recipe. The usual fan offset between ovens is not part of their rule.

The time is divided by the share kept rather than raised by 20%, so 20 minutes returns to 25 minutes, not 24 minutes.

Frozen food follows a different rule: for many frozen items, Instant Brands keeps the temperature and cuts the cooking time by around 50%.

With no frozen mode, the same result comes from a cut of 0°C and a time share of 50%. Breaded or coated food marked 200°C for 24 minutes then reads 200°C for 12 minutes.

The Food Standards Agency (FSA) points cooks to the instructions for the appliance or on the food packet, and packs of oven chips and oven-ready meals carry their own. For chips and roast potatoes, its acrylamide advice is a golden yellow colour or lighter. It names no temperature limit, so no starch warning appears here.

Hot air has to reach every surface, so the way the basket is filled matters alongside the setting.

• Single layer: COSORI UK cooks in a single, even layer, and Instant Brands warns against overcrowding the basket.
• Shake or turn halfway: Instant Brands moves the food at the midpoint, which the result gives as a time.
• Space around food: the FSA gives chicken legs in an air fryer as its example.
• Parchment paper: a sheet in the basket covers part of the floor the air passes through.

The FSA's test for cooked food is the same in any appliance: the middle of the food reaching 70°C for 2 minutes. A clean food thermometer measures that internal temperature.

Many models also offer air fry, roast and bake modes, while the published rule names no mode. Other makers, Ninja among them, showed no general oven rule on the pages read on 5 October 2026. The site's approach to sources is set out in the methodology.