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The Fryer Guide

Oven to Air Fryer Converter (UK, With Sources)

Enter an oven temperature and a recipe or pack time. The Fryer Guide shows the result from two different manufacturers' own published rules side by side, because they don't agree with each other, and Ninja's own documents don't fully agree with themselves.

Brands disagree on this. Treat every result below as a starting point, and check food is properly cooked rather than relying on time alone.

Static conversion table (no JavaScript needed)

If JavaScript is unavailable, use this table instead. It shows fresh-food oven recipes converted by Instant's fresh-food rule (Reduce the oven temperature by 20°C and cut the time by 20 to 25%.) and by Ninja's temperature-only rule (Reduce the oven temperature by 10°C and check food frequently. Ninja's booklets don't give a matching time adjustment.), plus one frozen-food example using Instant's frozen rule (Keep the oven temperature the same and cut the time by about 50%.).

Oven recipes converted two ways
Oven recipe Instant rule Ninja 10°C rule
160°C, 30 min (fresh) 140°C, 23-24 min 150°C, keep your recipe time (Ninja gives no time rule)
170°C, 30 min (fresh) 150°C, 23-24 min 160°C, keep your recipe time (Ninja gives no time rule)
180°C, 30 min (fresh) 160°C, 23-24 min 170°C, keep your recipe time (Ninja gives no time rule)
190°C, 30 min (fresh) 170°C, 23-24 min 180°C, keep your recipe time (Ninja gives no time rule)
200°C, 30 min (fresh) 180°C, 23-24 min 190°C, keep your recipe time (Ninja gives no time rule)
220°C, 30 min (fresh) 200°C, 23-24 min 210°C, keep your recipe time (Ninja gives no time rule)
200°C, 30 min (frozen) 200°C, 15 min 190°C, keep your recipe time (Ninja gives no time rule, and no separate frozen rule)

Where brands disagree

Ninja's own instruction booklets (AF100UK, AF300UK, AF400UK) say to reduce the oven temperature by 10°C. The AF400UK quick start guide gives a different rule for foods not on its chart: cut the packaging time by 25%, without changing temperature. Instant's guidance adjusts both temperature and time together. The brands don't agree with each other, and Ninja doesn't fully agree with itself across its own documents, so this page shows more than one rule rather than picking one.

Brands with no published conversion formula

UK gas mark, fan and conventional oven table

Fan and conventional oven columns as published by B&Q. B&Q is a UK retailer, not a government or standards body; no other working source for this table was found this session. B&Q's own rule of thumb: fan ovens usually need a lower temperature than a conventional (bake) setting, about 20°C lower for the same result.

Gas mark to Celsius and Fahrenheit (source: B&Q)
Gas mark Fan °C Conventional °C °F
1/2 110 130 250
1 120 140 275
2 130 150 300
3 150 170 325
4 160 180 350
5 170 190 375
6 180 200 400
7 200 220 425
8 210 230 450
9 220 240 475

Frequently asked questions

Which conversion rule should I use?
Instant's rule is used as the default here because it gives both a temperature and a time adjustment: Reduce the oven temperature by 20°C and cut the time by 20 to 25%. Ninja's rule (Reduce the oven temperature by 10°C and check food frequently. Ninja's booklets don't give a matching time adjustment.) is shown alongside it because it's also a genuine manufacturer rule, just for temperature only.
Why do Ninja and Instant disagree?
Ninja's own instruction booklets (AF100UK, AF300UK, AF400UK) say to reduce the oven temperature by 10°C. The AF400UK quick start guide gives a different rule for foods not on its chart: cut the packaging time by 25%, without changing temperature. Instant's guidance adjusts both temperature and time together. The brands don't agree with each other, and Ninja doesn't fully agree with itself across its own documents, so this page shows more than one rule rather than picking one.
Does this work for every air fryer brand?
No. Tower, Salter, Cosori and Philips do not publish their own oven-to-air-fryer conversion formula on their official UK sites or manuals, as far as this site has found; see the notes below the calculator.
Where does the gas mark table come from?
From B&Q (diy.com), a UK retailer, not a government or standards body. No working BBC Good Food gas-mark page could be found this session.

See the times already worked out: all air fryer cooking times.