Fan Oven Temperature Calculator

Work out fan oven temperature instantly with clear inputs, formula shown and shareable results.

About Fan Oven Temperature Calculator

A fan oven circulates air so it cooks as though it were about 20 C hotter, which is why recipes written for conventional ovens are reduced by 20 C for fan. Skipping the adjustment overcooks the outside of cakes and pastry by a noticeable margin, and the gas mark equivalent matters for older recipe books.

Formulas

Fan adjustment

fan temperature = conventional temperature - 20 C

Fahrenheit

F = C x 9 / 5 + 32

Worked example

With the default values below, Fan Oven Temperature Calculator returns Converted temperature of 180. Change any input above and every figure here is recalculated in your browser.

Inputs used

Temperature given in the recipeaccepts 50–300 C: 200 C
Convertone of Conventional to fan (subtract 20 C), Fan to conventional (add 20 C): Conventional to fan (subtract 20 C)

Results

Converted temperature: 180 C
In Fahrenheit: 356 F
Nearest gas mark: 5
Change applied: -20 C

Step by step

1Values used
2Fan adjustment
3Fahrenheit
4Converted temperature= 180 C
5In Fahrenheit= 356 F
6Nearest gas mark= 5
7Change applied= -20 C

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Fan Oven Temperature figure worked out?

fan temperature = conventional temperature - 20 C. A fan oven circulates air so it cooks as though it were about 20 C hotter, which is why recipes written for conventional ovens are reduced by 20 C for fan.

Why does this matter?

Skipping the adjustment overcooks the outside of cakes and pastry by a noticeable margin, and the gas mark equivalent matters for older recipe books.

What do I need to enter?

Enter temperature given in the recipe, convert. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.