Oven Temperature Conversion: Gas Mark to Fahrenheit and Celsius
Old recipes almost never use the oven scale you have in your kitchen. A British cookbook calls for gas mark 4, an American one says 350 degrees, and a modern fan oven wants something different again.
This converter turns any oven temperature into all three at once. Enter a number, pick the scale it is written in, and it gives you the gas mark, the Fahrenheit, and the Celsius, plus how hot that oven actually runs.
Oven Temperature Converter
Convert between Fahrenheit, Celsius, and gas mark in one step. Enter a temperature, choose the unit it is in, and the converter shows the nearest standard oven setting in all three scales.
Full Oven Temperature Conversion Chart
| Gas Mark | Fahrenheit | Celsius | Oven Heat |
|---|---|---|---|
| 1/4 | 225°F | 110°C | Very slow |
| 1/2 | 250°F | 130°C | Very slow |
| 1 | 275°F | 140°C | Slow |
| 2 | 300°F | 150°C | Slow |
| 3 | 325°F | 170°C | Moderate |
| 4 | 350°F | 180°C | Moderate |
| 5 | 375°F | 190°C | Moderately hot |
| 6 | 400°F | 200°C | Fairly hot |
| 7 | 425°F | 220°C | Hot |
| 8 | 450°F | 230°C | Very hot |
| 9 | 475°F | 240°C | Very hot |
Values are rounded to the standard UK oven settings used in most recipe books. Fan (convection) ovens usually run about 20°C, or one gas mark, cooler than the figures shown.
How to Read Old Oven Temperatures
For most of the 20th century, British ovens were marked in gas marks, a numbered dial running from a quarter up to nine. American ovens used Fahrenheit, and the rest of the world settled on Celsius.
Older recipes are worse still. A Victorian cookbook might just say “a moderate oven” or “a quick oven,” trusting the cook to know what that meant. A moderate oven is gas mark 4, which is 350 degrees Fahrenheit or 180 degrees Celsius.
If you are working from a genuine old recipe with vague measures as well as vague temperatures, our vintage measurement converter handles the teacups, gills, and “butter the size of an egg” side of the problem.
The Conversions People Look Up Most
- Gas mark 4 is 350°F or 180°C. This is the moderate oven most baking starts from.
- 180°C is gas mark 4, or 350°F.
- 350°F is gas mark 4, or 180°C.
- Gas mark 6 is 400°F or 200°C, a fairly hot oven for pastry and roasting.
- Gas mark 7 is 425°F or 220°C, hot enough for Yorkshire puddings and crisp roast potatoes.
Full Gas Mark to Fahrenheit to Celsius Chart
Here is the complete conversion chart for every gas mark, with the oven description that old recipes often use instead of a number.
| Gas mark | Fahrenheit | Celsius | Oven description |
|---|---|---|---|
| 1/4 | 225°F | 110°C | Very cool / very slow |
| 1/2 | 250°F | 130°C | Very cool |
| 1 | 275°F | 140°C | Cool / slow |
| 2 | 300°F | 150°C | Slow |
| 3 | 325°F | 170°C | Warm / moderately slow |
| 4 | 350°F | 180°C | Moderate |
| 5 | 375°F | 190°C | Moderately hot |
| 6 | 400°F | 200°C | Fairly hot |
| 7 | 425°F | 220°C | Hot |
| 8 | 450°F | 230°C | Very hot |
| 9 | 475°F | 240°C | Very hot |
These are the standard conventional-oven figures. If you have a fan oven, read the next section before you set the dial.
Fan Oven vs Conventional Oven
A fan oven (also called convection) moves hot air around, so it cooks faster and hotter than the dial suggests. The standard rule is to set a fan oven about 20 degrees Celsius, or one gas mark, lower than a conventional recipe asks for.
So a recipe written for gas mark 5 (375°F, 190°C) in a conventional oven becomes roughly 170°C in a fan oven. The converter above already does this adjustment for you in the result.
Oven Temperature FAQ
What is gas mark 4 in Fahrenheit and Celsius?
Gas mark 4 is 350 degrees Fahrenheit, or 180 degrees Celsius. It is a moderate oven and the most common baking temperature.
What is 180°C in gas mark?
180 degrees Celsius is gas mark 4, which is also 350 degrees Fahrenheit.
What is 350°F in gas mark?
350 degrees Fahrenheit is gas mark 4, or 180 degrees Celsius.
What is gas mark 5 in a fan oven?
Gas mark 5 is 375°F or 190°C in a conventional oven. In a fan oven, set it about 20 degrees lower, around 170°C.
What temperature is a moderate oven?
A moderate oven is 350°F, 180°C, or gas mark 4. A “slow” oven is around gas mark 1 to 2, and a “hot” oven is gas mark 7 and above.
For more on the old kitchen terms behind these settings, see the old recipe ingredient glossary, or put the whole thing in context with our cooking history timeline. Ready to use a very hot oven properly? Try the traditional Yorkshire pudding recipe.