Oven temperature conversion chart
Recipes describe oven heat in at least four incompatible systems: Fahrenheit in the US, Celsius across most of the world, gas marks in the UK and Ireland, and vague words like "moderately hot" in older cookbooks. Here is the full cross-reference.
The full chart
| Fahrenheit | Celsius | Fan / convection | Gas mark | Description |
|---|---|---|---|---|
| 225°F | 110°C | 90°C | ¼ | Very cool |
| 250°F | 120°C | 100°C | ½ | Very cool |
| 275°F | 140°C | 120°C | 1 | Cool |
| 300°F | 150°C | 130°C | 2 | Cool |
| 325°F | 160°C | 140°C | 3 | Warm |
| 350°F | 180°C | 160°C | 4 | Moderate |
| 375°F | 190°C | 170°C | 5 | Moderately hot |
| 400°F | 200°C | 180°C | 6 | Fairly hot |
| 425°F | 220°C | 200°C | 7 | Hot |
| 450°F | 230°C | 210°C | 8 | Very hot |
| 475°F | 240°C | 220°C | 9 | Very hot |
Fan ovens run hotter than the dial says
A fan circulates air, which transfers heat to food faster than still air at the same temperature. The standard correction is to set a fan oven about 20°C (or 25-30°F) lower than a conventional recipe specifies.
Some ovens apply this correction internally when you select the fan setting. If yours does, applying it again will underbake everything. Check the manual once and then you will know.
The exact formulas
Note the chart rounds to convenient dial numbers. 350°F is exactly 176.7°C, but every recipe in the world writes it as 180°C.
- Fahrenheit to Celsius: subtract 32, multiply by 5, divide by 9.
- Celsius to Fahrenheit: multiply by 9, divide by 5, add 32.
- Conventional to fan: subtract 20°C.
- Gas mark to Fahrenheit: multiply the mark by 25 and add 250 (rough but reliable from mark 1 to 9).
Your oven is probably lying
Home ovens are commonly off by 15-25°F, and they cycle above and below the set point as the thermostat switches the element. An inexpensive oven thermometer left on the middle shelf tells you your real temperature, and often explains why one recipe always burns and another never browns.
- Check with a separate thermometer after a full 20-minute preheat.
- Rotate trays halfway through if your oven has hot spots.
- Bake on the middle shelf unless a recipe says otherwise.
- Avoid opening the door in the first two-thirds of a cake bake.
Frequently asked questions
What is 350°F in Celsius?
350°F is 176.7°C exactly, universally rounded to 180°C. In a fan oven use 160°C.
What gas mark is 180°C?
Gas mark 4, the most common baking temperature in British recipes.
Should I reduce the temperature for a fan oven?
Yes, by about 20°C, unless your oven already compensates automatically when the fan setting is selected.
Why does my oven not match the recipe?
Most domestic ovens are miscalibrated by 15-25°F and cycle around the set point. Verify with an oven thermometer and adjust your dial accordingly.