Oven Temperature Converter — Gas Mark, Celsius, Fan & Fahrenheit
This oven temperature converter speaks every language your recipes do: type a value into any box — Gas Mark, conventional Celsius, fan Celsius or Fahrenheit — and the other three update instantly. No more guessing what Gas Mark 4 means on a modern oven dial.
Oven description: Moderate — fan ovens run about 20°C lower than conventional.
The complete oven temperature chart
This is the standard chart used in British cookbooks. Notice the pattern: each Gas Mark step is one notch hotter, and the fan temperature is always 20°C below the conventional one. If you only memorise one line, make it Gas Mark 4 — 180°C, 160°C fan, 350°F — because that is where most cakes are baked.
| Gas Mark | °C (Conventional) | °C (Fan) | °F | Description |
|---|---|---|---|---|
| ¼ | 110°C | 90°C | 225°F | Very slow |
| ½ | 120°C | 100°C | 250°F | Very slow |
| 1 | 140°C | 120°C | 275°F | Slow |
| 2 | 150°C | 130°C | 300°F | Slow |
| 3 | 170°C | 150°C | 325°F | Moderately slow |
| 4 | 180°C | 160°C | 350°F | Moderate |
| 5 | 190°C | 170°C | 375°F | Moderately hot |
| 6 | 200°C | 180°C | 400°F | Hot |
| 7 | 220°C | 200°C | 425°F | Hot |
| 8 | 230°C | 210°C | 450°F | Very hot |
| 9 | 240°C | 220°C | 475°F | Very hot |
Fan oven? Just take off 20°C
A fan oven circulates hot air, so food cooks faster and at a lower setting than in a conventional oven. The golden rule: whatever the recipe says, subtract 20°C for fan. A fruit cake at 150°C conventional goes in at 130°C fan; a roast at 200°C becomes 180°C fan.
The description words matter too. Recipes that say "moderate" mean Gas Mark 4 territory — the home of sponges, scones at a lower heat and most traybakes. "Moderately hot" (Mark 5) suits pastry, while Marks 7–8 are for bread, pizza and anything that needs a fierce blast to rise or crisp. Slow ovens (Marks ¼–2) are for meringues, fruit cakes and long braises.
One honest caution: oven dials lie. If your cakes consistently brown too fast or too slowly, an inexpensive oven thermometer tells you the truth — and the converter above will always give you the right target to aim at.
Frequently asked questions
What is Gas Mark 4 in Celsius and Fahrenheit?
Gas Mark 4 is 180°C in a conventional oven, 160°C in a fan oven, and 350°F. It is the classic "moderate" temperature used for most cakes, including a Victoria sponge.
How much lower should a fan oven be?
Reduce the conventional temperature by 20°C for a fan oven. So a recipe that says 200°C conventional becomes 180°C fan. If a recipe already states a fan temperature, use it exactly as written.
What is 350°F in Celsius and Gas Mark?
350°F is 180°C, which is Gas Mark 4 (160°C in a fan oven). American recipes bake most cakes at 350°F, which is why it matches the most common British setting.
Why do older British recipes use Gas Mark?
Gas Mark was introduced on British gas cookers in the 1940s and became the standard in classic cookbooks. Each Gas Mark step is roughly 13–14°C (25°F), running from very slow at Mark ¼ to very hot at Mark 9.
Is 180°C the same in every oven?
No — 180°C conventional is 160°C fan and 350°F. Always check which scale a recipe uses. When a modern British recipe just says "180°C" with no fan note, it usually means a conventional oven, so fan users should set 160°C.
Put it to work
Three favourite bakes, three different temperatures — convert as you go: