Last updated: 2026-06-16

An air fryer is a compact convection oven. A fan circulates hot air rapidly around the food, transferring heat more evenly and efficiently than the radiant heat of a conventional oven. Because of this, the same browning and cooking effect is achieved at a lower temperature and in less time — which is why conventional oven recipes need to be adjusted before using them in an air fryer.

The conversion rule

The widely used rule of thumb has two parts: lower the temperature by 25 °F (about 15 °C) and reduce the cooking time by 20%. A secondary checkpoint — starting to check the food at about two-thirds of the original oven time — helps avoid overcooking, since air fryers vary in how aggressively they circulate heat.

Worked example

A recipe calls for roasting chicken thighs at 400 °F for 25 minutes in a conventional oven.

The air fryer is set to 375 °F, and the thighs are checked at about 16–17 minutes — two-thirds of the original 25 minutes — to gauge doneness before the full 20 minutes have elapsed.

Variation between models

The 25 °F / 20% rule is a starting point, not a guarantee. Air fryer models differ in basket size, fan speed, and heating element placement. Compact basket-style fryers tend to run hotter and faster than oven-style models; crowded baskets slow down cooking because air cannot circulate freely. Foods with a high moisture content take longer than the rule suggests, while thin or small pieces cook faster. For meat and poultry, a food thermometer provides the most reliable confirmation of doneness regardless of the time shown.

Not all recipes benefit from air frying. Dishes that depend on steam or a moist enclosed environment — casseroles, custards, bread baked under a cover — do not suit the dry circulating air. Wet batters can drip and smoke; dry breadcrumb or flour coatings work much better.

For roasting time estimates by weight, see the Turkey Roasting Time Calculator.