Fan Oven Temperature Converter

This free fan oven temperature converter turns a conventional oven temperature into the right fan oven setting, or a fan setting back into a conventional one, for home cooks in the UK and Europe. It works in Celsius or Fahrenheit, shows the matching gas mark, and lets you set the fan reduction your oven manual recommends.

Quick answer: A fan oven temperature converter subtracts about 20 °C (36 °F) from a conventional recipe temperature. So 180 °C conventional becomes 160 °C fan, 200 °C becomes 180 °C fan and 220 °C becomes 200 °C fan. To go from fan to conventional, add the 20 °C back on.

What Is a Fan Oven Temperature Converter?

A fan oven temperature converter adjusts a recipe temperature so food cooks the same in a fan oven as it would in a conventional oven with top and bottom heat. A fan circulates hot air around the food, which transfers heat faster, so the same result needs a lower setting.

The formula in plain words: fan temperature equals conventional temperature minus the fan reduction. The default reduction is 20 °C, the figure given for convection ovens on Wikipedia. In Fahrenheit, the reduction is 20 x 9 / 5 = 36 °F. Going the other way, conventional temperature equals fan temperature plus the reduction.

How Do You Use the Fan Oven Temperature Converter?

1. Choose the Direction: “Conventional to fan oven” for most recipes, or “Fan oven to conventional” if you have a recipe written for fan and a conventional oven.
2. Set the Temperature unit to “Celsius °C” or “Fahrenheit °F” to match your recipe.
3. Type the figure from your recipe into Recipe temperature.
4. Check Fan oven reduction. Keep 20 °C unless your oven manual gives a different figure.
5. Read the fan or conventional setting, the other unit and the gas mark, then open “Show the formula and working” to check each step.

How Much Do You Reduce the Temperature for a Fan Oven?

Reduce the temperature by about 20 °C for a fan oven, which is 36 °F if your recipe is in Fahrenheit. Manufacturers give the same guidance: AEG’s true fan cooking guide says you can reduce the temperature by 20 °C compared with conventional cooking. Your own oven’s manual is the best guide, which is why the reduction is editable.

What Is 180 °C in a Fan Oven?

180 °C in a conventional oven is 160 °C in a fan oven. Conventional 180 °C is also 356 °F and gas mark 4. It is one of the most common baking temperatures in UK recipes.

When Should You Not Reduce the Temperature?

Do not reduce the temperature when the recipe already gives a fan figure, or when you cook on your oven’s conventional setting with the fan switched off. Many UK recipes and food packs list both, such as “200 °C, 180 °C fan, gas mark 6”. Use the fan figure directly in that case. Subtracting again would leave food undercooked, so always check which figure the recipe means.

Do Fan Ovens Cook Faster?

Fan ovens transfer heat faster at the same setting, which is why the temperature is lowered rather than the cooking time. At the reduced setting, most dishes take roughly the time the recipe states, but start checking a few minutes early. For meat, judge doneness with a food thermometer in the thickest part rather than by time. To see what each hour of cooking costs, the electricity cost calculator shows what each hour of cooking costs.

Fan Oven Conversion Chart

Fahrenheit values are exact conversions of the Celsius figures, rounded to the nearest degree, with a 20 °C reduction for fan.

Worked Example: Roasting Vegetables in a Fan Oven

Example: a tray bake recipe says to roast the vegetables at 200 °C, with no fan figure given, and the oven is a fan oven. Leave Direction on “Conventional to fan oven”, keep Temperature unit on “Celsius °C”, enter 200 in Recipe temperature and leave Fan oven reduction at 20 °C.

The tool works out 200 °C minus 20 °C = 180 °C fan, which is 356 °F. The breakdown shows the conventional 200 °C matches gas mark 6, so set the fan oven to 180 °C and check the vegetables a few minutes before the recipe time.

Fan Oven Temperature Converter FAQs

For more tools that help with home running costs, browse our energy bill calculators.

Checked October 2026. Sources: Wikipedia: Convection oven, AEG: What is true fan cooking, Wikipedia: Gas mark.