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Fan-Forced Oven Temperature Conversion

180 °C (conventional recipe) is 160 °C, gas mark 4.

Try your own numbers

For a gas mark, type 1/4, 1/2 or a number from 1 to 9.

The recipe is written for a
My oven is a
Assumptions (editable)
°C
°F

A fan-forced oven is set lower than a conventional oven for the same recipe. 20 °C is the usual figure (Which?) and 25 °F the usual US rule of thumb. Both are editorial rules of thumb, and 20 °C is 36 °F, so they are not the same size. Many ovens adjust automatically. Check your manual.

Set your oven to160 °C
Exact in °C160 °C
Exact in °F320 °F
Nearest gas markGas mark 4 (180 °C)

The recipe is for a conventional oven and yours is a fan-forced oven, so 20 °C comes off: 180 − 20 = 160 °C. 160 °C × 9 ÷ 5 + 32 = 320 °F. The dial value is rounded to the nearest 10 °C or 25 °F.

Ovens vary, so use an oven thermometer to check.

Fig. 1 The converted oven temperature.

Every formula is tested against worked examples. How we check

Gas markConventional °CConventional °FFan-forced °CFan-forced °F
¼110 °C225 °F90 °C200 °F
½120 °C250 °F100 °C225 °F
1140 °C275 °F120 °C250 °F
2150 °C300 °F130 °C275 °F
3160 °C325 °F140 °C300 °F
4180 °C350 °F160 °C325 °F
5190 °C375 °F170 °C350 °F
6200 °C400 °F180 °C375 °F
7220 °C425 °F200 °C400 °F
8230 °C450 °F210 °C425 °F
9240 °C475 °F220 °C450 °F

Fig. 2 Common oven temperatures on every scale, with the fan-forced setting. Gas marks are for conventional ovens.

Last checked 11/11/2026. Sources: Which?: Oven temperature conversion table (gas marks 1 to 9 with fan temperatures; fan ovens about 20 °C lower); Wikipedia: Gas mark (gas marks ¼ and ½; marks rise 25 °F each; prints 170 °C for gas mark 3).

Fan-Forced Oven Temperature Conversion: the working

Many Australian recipes are written for a conventional oven and say to reduce the temperature by 20 °C for fan-forced. Some ovens do this for you.

The recipe is for a conventional oven and yours is a fan-forced oven, so 20 °C comes off: 180 − 20 = 160 °C. 160 °C × 9 ÷ 5 + 32 = 320 °F. The dial value is rounded to the nearest 10 °C or 25 °F.

Common questions

What is the exact conversion?

160 °C is 320 °F. The dial value is rounded to 160 °C or 325 °F.

Do I need to change it for a fan-forced oven?

A recipe written for a conventional oven is usually set about 20 °C (25 °F) lower in a fan-forced oven. Many ovens do this for you, so check your manual and your oven thermometer.

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