A recipe says 350°F and your oven dial is in Celsius? Type either temperature and the other is filled in, with the fan (convection) setting and the gas mark alongside. The chart below covers every common oven setting.
Fan / convection-
Gas mark-
Oven description-
For a fan (convection) oven, most recipes work well about 25°F / 15°C lower, or at the same temperature with a shorter time.
| Fahrenheit | Celsius | Fan | Gas mark | Description |
|---|---|---|---|---|
| 225°F | 110°C | 90°C | 1/4 | Very cool |
| 250°F | 120°C | 100°C | 1/2 | 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 | 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 |
| 500°F | 260°C | 240°C | 10 | Extremely hot |
Fan ovens
A fan or convection oven moves hot air around, so food cooks faster. Most recipes work well with the fan setting about 25°F (15-20°C) lower than the conventional temperature, or the same temperature with a shorter time.
Oven thermometer
Many ovens run hot or cold by 25°F or more. A cheap oven thermometer tells you what the oven is really doing, and explains why a recipe that "always works" suddenly does not.