Why the temperature goes down
An air fryer is a compact convection oven. Its fan pushes hot air fast across a small chamber, stripping away the layer of cooler air that normally insulates food. The same 400° on the dial therefore cooks faster and browns harder than a full-size oven — so to get the result a recipe author intended, you lower the temperature about 25°F (15°C) and cut the time about 20%.
The two rules this calculator uses
- From a conventional oven recipe: −25°F (−15°C), −20% time.
- From a fan/convection oven recipe: −10°F (−5°C), −10% time — fan ovens already behave halfway like an air fryer.
Temperatures are rounded to the nearest 5°, because that's how air fryer dials work. The reverse tab applies the inverse rule: temperatures convert back exactly, while times can drift by a minute either way since minutes are rounded — treat reverse results as a starting point too.
What conversion can't fix
Two honest caveats. First, machines differ: a 1,200 W compact basket and a 1,800 W family drawer are different animals, so treat any converted time as a starting point and check early. Second, load size matters — a crowded basket steams instead of crisping. Cook in a single layer, shake halfway, and add a minute or two rather than stacking food.
FAQ
What is 400°F oven in an air fryer?
375°F, with about 20% less time — 20 minutes becomes 16. (200°C becomes about 185°C.)
Is air fryer 400° the same as oven 400°?
No — the fan and small chamber make it cook faster and brown harder at the same dial number. That's the whole reason the conversion exists.
My recipe is for a fan oven — same rule?
Smaller adjustment: −10°F (−5°C) and −10% time. Set "fan / convection oven" in the calculator.
Do I need to preheat?
Usually no, or just 2–3 minutes for extra-crisp results — baskets heat up almost instantly.
Food came out done early — why?
Wattage and basket size vary a lot between models. Check 2–3 minutes early the first time, then write down what your machine actually needed.