Air Fryer Conversion Calculator

Convert an oven recipe to air fryer settings, and back, with each manufacturer’s own published rule rather than a blog’s average — and with the arithmetic mistake in the familiar “25 °F, about 20 °C” shorthand shown rather than repeated. A 25 Fahrenheit-degree drop is 13.9 °C. Time is an estimate here; internal temperature decides.

Last updated 24 Sep 2026

Oven to air fryer, and back

Recipe → air fryer settings

Which way?

Temperature in the recipeWhatever the recipe says, in the unit beside it.

Time in the recipe (minutes)The recipe’s own cooking time. What comes back is an estimate: the thermometer decides when it is done.

Whose temperature rule?Four makers, four answers, and two of them are not even the same size. The table below has each one in its own words.

Your own temperature drop (°C)Only used when the box above says “Your own figure”.

Time reduction (%)Cuisinart say about 20. Instant say 20 to 25 for fresh food and about 50 for frozen. Ninja publish no rule and claim up to 65. There is no consensus to default to, so this is yours.

How is the basket loaded?Every maker’s rule assumes a single layer. On a crowded basket this page returns no time at all, because it does not have one to give.

A geometry, not a circuit: an oven cavity and an air fryer basket in section, both at the same scale of one pixel to four millimetres, with the element-to-food distance dimensioned on each. That distance is the physical reason the two behave differently — about 180 mm in an oven against about 45 mm in a basket, so the food sees far more radiant heat from the element as well as faster air — and the cavity volumes differ by more than ten times. The arrows are the circulation: one slow loop in the oven, several fast ones in the basket. Dimensions are typical domestic sizes rather than any one model's. The temperature figures below are exact arithmetic; the time is an estimate, and internal temperature is what decides.

180°CExample

a 200 °C oven recipe for 25 minutes, on Instant’s rule for fresh food, in a single layer

Two adjustments, one of which is not a doneness figure

air fryer °C = oven °C − ΔT · air fryer minutes = oven minutes × (1 − cut) · oven °C = air fryer °C + ΔT · oven minutes = air fryer minutes ÷ (1 − cut) · ΔT in °C = ΔT in °F × 5/9

ΔT: the temperature drop. Cuisinart’s 25 Fahrenheit degrees is 13.89 °C; Instant’s is a round 20 °C, which is 36 Fahrenheit degrees. They are different rules, not different units
× 5/9: how a temperature INTERVAL converts. The 32 belongs to a scale reading, not to a difference, and leaving it in is what turns 25 °F into a mistaken 20 °C
cut: the time reduction. Published figures run from 20% to 50%, plus one maker’s unexplained 65%. There is no consensus, so it is yours to set
single layer: every maker’s rule assumes it. A crowded basket is a small oven, not a fryer, and this page returns no time for one
the thermometer: what actually decides. The converted time is where to start checking, never a guarantee

Worked example

a 200 °C oven recipe for 25 minutes, on Instant's rule for fresh food, in a single layer
Instant's rule for fresh food is 20 °C cooler, so 200 − 20 = 180 °C
Cuisinart's rule would be 25 Fahrenheit degrees cooler, which is 13.89 °C, so 186.1 °C — 6.1 °C higher than Instant's. The two published rules are not the same size
At a 20% time reduction, 25 × 0.80 = 20 minutes. At Instant's own upper figure of 25% it is 18.8, and on Ninja's “up to 65%” it would be 8.8
That time is an estimate and nothing more. Start checking the internal temperature at about 14 minutes
For poultry the target is FSIS's 165 °F, 73.9 °C, in the thickest part; for a whole cut of beef, pork, lamb or veal it is 145 °F, 62.8 °C, with a three-minute rest. A converted time is not a substitute for either

Four makers, in their own words

Read the first two rows together, because this is the arithmetic mistake the “25 °F (about 20 °C)” shorthand is built on. A DROP of 25 °F is a drop of 13.89 °C, not 20 °C — you convert a temperature interval by multiplying by 5/9, and you do not add the 32. A drop of 20 °C is 36 Fahrenheit degrees. So Cuisinart’s rule and Instant’s are not two spellings of one rule: Instant’s is 1.44 times as large, 6.1 °C or 11 Fahrenheit degrees further down. The third row is a different rule again — frozen food gets no temperature change at all and half the time — and the fourth publishes nothing to compare.
Maker	Temperature drop (°C)	… in Fahrenheit degrees	What they publish
Cuisinart	13.89	25.0	Cuisinart: “Reduce the temperature by about 25°F when baking” and “Reduce the cooking time by about 20%.”
Instant, fresh food	20.00	36.0	Instant Brands UK: “Reduce the oven temperature by 20°C and reduce the cooking time by 20–25%.”
Instant, frozen food	0.00	0.0	Instant Brands UK: “Keep the oven temperature the same and reduce the cooking time by around 50%.”
Ninja	—	—	Publishes a per-food chart and no conversion rule at all, with the claim that its air fryers cut “cooking times down by up to 65%”.

The time reduction: four published answers on one 25 minute recipe

From 20 minutes to 8¾ on the same recipe — a factor of 2.29 between the extremes of what four manufacturers publish. Ninja’s 65% is not offered as a conversion rule and should not be used as one; it is quoted here to show the width of the disagreement. This is why the reduction is an input on this page rather than a constant, and why the number it returns is labelled an estimate. Nothing here is a doneness figure.
Source	What it says	Reduction (%)	25 oven minutes becomes
Cuisinart	“about 20%”	20	20.0
Instant, fresh	“20–25%”	20 to 25	18.8 to 20.0
Instant, frozen	“around 50%”, with NO temperature change	50	12.5
Ninja	no conversion rule published; “cutting cooking times down by up to 65%”	65	8.8

How much of the adjustment is just the fan?

An air fryer is a small convection oven with a fast fan and a short distance from element to food. Part of why it cooks faster is therefore exactly the fan-oven effect, which is already a published 20 °C convention. But the makers’ own instructions rule out the tidy conclusion that the air-fryer rule IS the fan rule: Instant apply their 20 °C on top of a fan-oven recipe, not instead of it. What is left over is the geometry — a 2 to 5 litre cavity, food a few centimetres from the element, and air moving fast enough to matter. That part is not a number anybody has published, and this page does not invent one.
Adjustment	Size (°C)	What it is for
Fan oven convention	20	Moving air strips the insulating boundary layer off the food, so a fan oven at 180 °C cooks like a conventional one at 200. The oven temperature converter owns this one.
Instant’s air fryer drop, fresh food	20	The same size as the fan convention — and Instant tell you to apply it AGAIN to a recipe already written for a fan oven. So it is not the fan offset relabelled.
Cuisinart’s air fryer drop	13.89	A 25 Fahrenheit-degree drop, which is 13.9 °C: about two thirds of the fan offset.
Instant’s frozen-food rule	0	No temperature change at all, and half the time. A conversion that is purely about time.

A small convection oven, four published rules, and one arithmetic mistake

An air fryer is a small convection oven. A fan, a heating element, a 2 to 5 litre cavity, and food sitting a few centimetres below the element instead of thirty. Nothing is fried. That description is the whole of why a recipe needs converting: moving air strips away the insulating layer of still air round the food, so heat arrives faster than the same oven temperature would suggest, and a small cavity with a short path from element to food does it harder again. Part of that effect already has a published number — the fan-oven convention of 20 °C, which the oven temperature converter owns. The rest is the size and the geometry, and no manufacturer has published a figure for it.

The famous rule is two rules, and one of them is an arithmetic mistake. “Reduce the temperature by 25 °F, about 20 °C” is printed everywhere, and 25 Fahrenheit degrees is not about 20 Celsius degrees — it is 13.89. A temperature DIFFERENCE converts by multiplying by 5/9; the 32 belongs to a scale reading and adding it to a difference is the error. Go to the makers instead and they genuinely disagree: Cuisinart publish 25 °F and about 20% off the time, Instant publish 20 °C and 20 to 25% off, and Instant’s drop is 1.44 times Cuisinart’s. Instant also publish a completely different rule for frozen food — no temperature change and about half the time — and Ninja publish no conversion rule at all, only a per-food chart and a claim of up to 65% time saved. Four sources, four answers, and a factor of 2.29 between the extremes on the same 25 minute recipe.

The tidiest theory does not survive the instructions. If the air-fryer adjustment were simply the fan-oven offset under another name, then a recipe already written for a fan oven would need no change at all. Instant say the opposite: reduce a fan-oven recipe by around 20 °C and 20 to 25% as well. Whatever the air fryer is doing beyond the fan, the maker who publishes the clearest rule treats it as an extra adjustment and not a substitute. This page therefore prints how much of your chosen drop the fan convention alone would account for, and leaves the remainder unexplained rather than attributing it to something nobody has measured.

Time is an estimate. Internal temperature is the answer. This is the part of the page that matters. Air fryers are used for chicken thighs, drumsticks, wings, burgers and sausages — food where the difference between done and not done is a food-safety difference and not a texture one — and a time reduction applied to a thick piece of poultry can leave the middle short while the outside looks finished. USDA FSIS require 165 °F (73.9 °C) in the thickest part of any poultry, and 145 °F (62.8 °C) with a three-minute rest for a whole cut of beef, pork, lamb or veal. No number this page returns is a doneness figure; the converted time is where to start checking. Every doneness band and every legal minimum lives on the meat cooking temperature converter, and a probe costs less than the meat.

One layer, or no answer. Every published rule assumes food in a single layer with air moving round each piece, and all three makers who say anything say not to crowd the basket. A piled basket is a small oven rather than a fryer: convection stops reaching the middle, the outside browns while the inside steams, and the time is longer by an amount nobody has quantified. Tell this page the basket is crowded and it returns the temperature and no time at all, because it does not have one to give. Cook in batches instead. Going the other way — an air fryer recipe into a conventional oven — is the less served direction and equally asked; the calculator does it, with the reminder that reversing a 20% cut means dividing by 0.8 and therefore adding 25%, not 20. For the °C, °F and gas-mark arithmetic itself, and for the fan setting, the oven temperature converter is the page.

Frequently asked questions

Is the air fryer rule 25 °F or 20 °C?

They are not the same rule, and the shorthand that treats them as the same is doing the temperature conversion wrong. A DIFFERENCE of 25 °F is a difference of 13.89 °C — you multiply an interval by 5/9 and you do not add the 32. A difference of 20 °C is 36 Fahrenheit degrees. Cuisinart publish the 25 °F version and Instant the 20 °C version, so the two makers genuinely disagree by about 6 °C, and the widely repeated “25 °F (about 20 °C)” is the two of them mashed together.

Is a converted time safe to cook to?

No. A time is an estimate; internal temperature is the thing that decides, and this matters most for exactly the food air fryers are used for. A chicken thigh given 20% less time than the oven recipe can sit below a safe internal temperature and look perfectly cooked. USDA FSIS require 165 °F (73.9 °C) in the thickest part of any poultry and 145 °F (62.8 °C) plus a three-minute rest for a whole cut of beef, pork, lamb or veal. Put a probe in it. The meat cooking temperature converter has every minimum and every doneness band; nothing on this page is a doneness figure.

Is an air fryer just a small fan oven?

Substantially, yes: a 2 to 5 litre cavity, a fast fan, and food a few centimetres from the element rather than thirty. That is why part of the adjustment is simply the fan-oven effect, which is already a published 20 °C convention — see the oven temperature converter. But the makers’ own instructions stop you concluding that the air-fryer rule IS the fan rule: Instant tell you to apply their 20 °C drop to a recipe that was already written for a fan oven. What is left over is the size and the geometry, and no manufacturer has published a number for that part.

Does a crowded basket change the answer?

It changes it enough that this page will not give you a time for one. Every maker’s conversion rule assumes a single layer with air moving round each piece; Cuisinart say “air fryers need space for air circulation”, Instant say “do not overcrowd the basket” and Ninja say to “avoid overfilling”. Piled food behaves like a small oven rather than a fryer: the outside browns, the middle steams, and the time is longer by an amount nobody has quantified. Cook in batches, or shake and allow considerably more time with a probe.

How do I go the other way, from an air fryer recipe to an oven?

Add the temperature back and divide the time instead of multiplying it. Set the direction at the top of the calculator and it does both. Note that dividing by 0.8 is not the same as adding 20% — a 20 minute air fryer time becomes 25 oven minutes, not 24 — which is the other small arithmetic trap in this conversion.

Why does frozen food have a different rule?

Because the limiting step is different. Instant’s published guidance for frozen food is to keep the oven temperature the same and cut the time by about half, where fresh food gets 20 °C off and 20 to 25% off. Frozen food has to absorb the latent heat of melting before its centre can rise at all, so the temperature gradient is doing useful work for longer and dropping the temperature would only stretch that out. It is the one row in the whole comparison where a maker changes the SHAPE of the rule rather than the size of it.

Related calculators

References

Cuisinart. The Air Fryer Conversion Chart. cuisinart.com. “Reduce the temperature by about 25°F when baking” and “Reduce the cooking time by about 20%”, with the maker’s own warning that “Air fryers need space for air circulation.”
Instant Brands UK. Air Frying 101: how to convert oven cooking times to your air fryer. instantpot.co.uk. Fresh food: “Reduce the oven temperature by 20°C and reduce the cooking time by 20–25%.” Frozen food: “Keep the oven temperature the same and reduce the cooking time by around 50%.” And, for a recipe already written for a fan oven, “reduce the temperature by around 20°C” AGAIN — which is why the air-fryer offset cannot be only the fan offset.
SharkNinja. Air Fryer Cooking Time Guide. ninjakitchen.co.uk. Publishes a per-food time and temperature chart and NO conversion rule at all, together with the claim that its air fryers cut “cooking times down by up to 65%”. The fourth published answer, and the furthest from the other three.
Which? (UK consumer association). The 20 °C fan-oven convention, as used by the oven temperature converter on this site. The comparison that matters on this page is that Instant’s air-fryer drop is the same size as the fan drop and is applied on top of it.
U.S. Department of Agriculture, Food Safety and Inspection Service. A work of the United States Government and in the public domain. Safe Minimum Internal Temperature Chart and Poultry: Basting, Brining, and Marinating. 145 °F (63 °C) with a three-minute rest for whole cuts of beef, pork, lamb and veal; 165 °F (74 °C) for all poultry. No converted TIME on this page is a doneness figure.