Oven temperatures: gas mark, °C, °F and fan
British recipes give gas marks, American ones Fahrenheit, European ones Celsius, and none of them say what to do with a fan oven. Enter the temperature the recipe gives and read the three others.
Gas 4 = 180 °C = 350 °F = 160 °C fan · Gas 6 = 200 °C = 400 °F
Fan (convection) ovens: recipe temperature minus 20 °C (25 °F). Gas mark: nearest mark on the 25 °F scale.
Conversion chart
Celsius figures are the rounded values printed in cookbooks (180 °C for gas 4, though 350 °F is 177 °C exactly); Fahrenheit follows the gas-mark scale of 25 °F per mark.
| Gas mark | °C conventional | °C fan | °F | Description |
|---|---|---|---|---|
| ¼ | 110 | 90 | 225 | Very slow |
| ½ | 120 | 100 | 250 | Very slow |
| 1 | 140 | 120 | 275 | Slow |
| 2 | 150 | 130 | 300 | Slow |
| 3 | 160 | 140 | 325 | Moderately slow |
| 4 | 180 | 160 | 350 | Moderate |
| 5 | 190 | 170 | 375 | Moderately hot |
| 6 | 200 | 180 | 400 | Moderately hot |
| 7 | 220 | 200 | 425 | Hot |
| 8 | 230 | 210 | 450 | Hot |
| 9 | 240 | 220 | 475 | Very hot |
| 10 | 260 | 240 | 500 | Very hot |
Fan, convection and conventional
A fan (convection) oven moves the air, so food heats faster at the same thermostat setting. The usual rule is to set it 20 °C below a conventional recipe, and most British cookbooks now print both figures ("200 °C / 180 °C fan"). American recipes rarely mention convection because most US ovens have a convection mode that lowers the temperature automatically by 25 °F when switched on.
The gas-mark scale, "Regulo" when it was introduced in the 1920s, was set so that each mark is 25 °F; the Celsius equivalents are approximations and vary by a few degrees between books. For exact temperature conversion outside the kitchen, use Celsius to Fahrenheit.
Frequently asked questions
180 °C conventional, 160 °C fan, 350 °F. It is the "moderate" oven of most cake recipes.
356 °F exactly, which recipes round to 350 °F (gas mark 4).
About 20 °C (or 25 °F) below the recipe temperature, and check 5 to 10 minutes earlier: moving air transfers heat faster. Some manufacturers say 10 to 15 °C; the oven manual wins.
Gas mark 6 (400 °F). 200 °C is 392 °F exactly, closest to the 400 °F mark.
Yes on paper: gas mark 1 is 275 °F and each mark adds 25 °F, so gas 9 is 475 °F. In practice gas ovens have hotter tops and bottoms and cycle around the set point, so treat any mark as a range of about ±10 °C.