A recipe from a British cookbook says “Gas Mark 4.” Yours is a fan oven with only Celsius on the dial. A cake recipe from a US site says “350°F.” None of this lines up until you do an oven temperature conversion — and getting it wrong by even one gas mark or twenty degrees can be the difference between a properly risen loaf and a dense, undercooked one. Here’s the full conversion chart, the formula behind it, and how to adjust for a fan oven.
Why Oven Temperature Conversion Trips People Up
Ovens are calibrated differently around the world. The US and much of Asia use Fahrenheit, most of Europe and India use Celsius, and older British recipes still reference “Gas Mark” numbers from stovetop gas ovens. On top of that, fan (convection) ovens circulate hot air and cook faster than conventional ovens at the same dial setting, so a straight Celsius-to-Fahrenheit conversion isn’t always enough — you also need to know whether your oven is fan-assisted.
The Oven Temperature Conversion Chart
Use this chart to convert between Fahrenheit, Celsius, and Gas Mark for common baking temperatures. Fan oven figures are roughly 20°C (or one gas mark) lower than conventional settings.
- Gas Mark 1 — 275°F / 140°C (fan: 120°C)
- Gas Mark 2 — 300°F / 150°C (fan: 130°C)
- Gas Mark 3 — 325°F / 160°C (fan: 140°C)
- Gas Mark 4 — 350°F / 180°C (fan: 160°C)
- Gas Mark 5 — 375°F / 190°C (fan: 170°C)
- Gas Mark 6 — 400°F / 200°C (fan: 180°C)
- Gas Mark 7 — 425°F / 220°C (fan: 200°C)
- Gas Mark 8 — 450°F / 230°C (fan: 210°C)
- Gas Mark 9 — 475°F / 240°C (fan: 220°C)
These figures are the standard rounded values used in most recipe books. Gas mark equivalents can vary slightly between oven manufacturers, so treat them as a reliable starting point rather than an exact science, and keep an oven thermometer handy if precision really matters for a recipe like macarons or bread.
The Formula Behind Oven Temperature Conversion
If your recipe gives a temperature that doesn’t land neatly on the chart above, you can calculate it directly. The standard formulas, as documented by the National Institute of Standards and Technology (NIST), are:
- Fahrenheit to Celsius: °C = (°F − 32) × 5/9
- Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Worked example: a recipe calls for 425°F. Subtract 32 to get 393, multiply by 5/9, and you get roughly 218°C — close enough to round to 220°C, which lines up with Gas Mark 7 on the chart above. You can plug any figure into our Unit Converter for an instant result without doing the math by hand.
Adjusting for a Fan (Convection) Oven
If your recipe was written for a conventional oven but you’re baking in a fan oven, reduce the temperature by about 20°C (or roughly 25°F), or drop down one gas mark. Fan ovens circulate air more evenly and cook faster, so using the conventional-oven temperature as written can over-brown the outside of a dish before the inside finishes cooking. If your oven has both settings marked on the dial, you can usually use those numbers directly instead of doing the math.
Common Baking Temperatures You’ll Actually Use
A handful of temperatures show up in recipes far more often than the rest, so it helps to have them memorized rather than reaching for a chart every time. Bread and pizza generally bake hot, around 220–230°C (Gas Mark 7–8), to get a good rise and a crisp crust quickly. Cakes and muffins usually sit in the middle range, around 160–180°C (Gas Mark 3–4), so the batter cooks through evenly without the outside browning too fast. Slow-roasted meats and casseroles often go as low as 140–150°C (Gas Mark 1–2) for a long cooking time that keeps the meat tender. Meringues and dried fruit go lower still, sometimes below 120°C, since the goal is drying out moisture rather than browning. Keeping these rough bands in mind makes it much easier to sanity-check a converted number — if your oven temperature conversion spits out something wildly outside these ranges for a cake or loaf, it’s worth double-checking the math.
Key Takeaways
- Oven temperature conversion between Fahrenheit, Celsius, and Gas Mark is essential when following recipes from a different region.
- The core formula is °C = (°F − 32) × 5/9, and °F = (°C × 9/5) + 32.
- Fan ovens typically need about 20°C (or one gas mark) less than a conventional oven setting.
- Gas mark equivalents are standardized approximations — small variations between ovens are normal.
FAQ
What is 180°C in Fahrenheit?
180°C converts to 356°F, which most recipes round to 350°F — the most common baking temperature and equivalent to Gas Mark 4.
Is Gas Mark the same across every oven brand?
Gas mark numbers are standardized, but the exact temperature an individual oven reaches at each mark can vary slightly. If your bakes consistently run hot or cool, an oven thermometer will tell you how far your oven’s actual temperature drifts from the dial.
Do I need to adjust baking time as well as temperature for a fan oven?
Often yes — fan ovens can also cook slightly faster even after the temperature is adjusted, so start checking a few minutes before the original recipe’s suggested time.
Need to convert other cooking measurements too? Try our Unit Converter or browse the full collection of calculators.