Oven temperature conversion made simple: Celsius, Fahrenheit, gas mark and fan ovens
Recipes travel. A cake from a UK cookbook says gas mark 4, an American blog says 350°F and your oven dial says 180°C. Get the temperature wrong and a sponge can sink, a batch of biscuits can burn, or a bake can stay raw in the middle.
Three scales, one oven
Celsius is used across most of the world, Fahrenheit is common in American recipes, and gas mark is a numbered scale found on gas ovens, mostly in the UK and Ireland. They all describe the same heat, just with different numbers.
Common oven temperatures at a glance
- Gas Mark ¼: 110°C / 225°F (very cool)
- Gas Mark ½: 120°C / 250°F (very cool)
- Gas Mark 1: 140°C / 275°F (cool)
- Gas Mark 2: 150°C / 300°F (cool)
- Gas Mark 3: 170°C / 325°F (warm)
- Gas Mark 4: 180°C / 350°F (moderate)
- Gas Mark 5: 190°C / 375°F (moderately hot)
- Gas Mark 6: 200°C / 400°F (fairly hot)
- Gas Mark 7: 220°C / 425°F (hot)
- Gas Mark 8: 230°C / 450°F (very hot)
- Gas Mark 9: 240°C / 475°F (very hot)
These are the rounded values printed in most recipe books. A strict conversion gives slightly different numbers, for example 180°C is exactly 356°F, but no home oven is accurate to a few degrees, so the rounded figures work perfectly well.
What about fan ovens?
A fan oven circulates hot air, so it cooks faster and more evenly than a conventional oven. As a rule of thumb, reduce the temperature by about 20°C (or around 25°F) when a recipe is written for a conventional oven. Some ovens and recipes differ, so check your oven manual if you are unsure.
For example, a recipe that asks for 180°C in a conventional oven (350°F, gas mark 4) needs about 160°C in a fan oven. If a recipe already says 160°C fan, a conventional oven needs 180°C.
Tips for accurate baking
- Check whether the recipe was written for a conventional or a fan oven before you convert
- Use an oven thermometer, as many ovens run hotter or cooler than the dial says
- Preheat fully before the tin goes in, which usually takes 15 to 20 minutes
- Avoid opening the door in the first half of the bake, especially for sponges and soufflés
Try the free converter
Our new oven temperature converter does the maths for you. Enter a temperature in Celsius, Fahrenheit or gas mark, say whether the recipe is for a conventional or a fan oven, and see the equivalent for both oven types, with a full gas mark chart underneath. It is free and needs no sign-up.