Oven Temperature Conversion: °F, °C, Gas Mark & Fan (The Only Chart You Need)
July 5, 2026
You find the perfect recipe. It says bake at 180°C. Your oven dial only shows Fahrenheit — or worse, it’s a gas oven and the recipe was written for gas mark 4. Guess wrong and a delicate sponge scorches, or a roast sits pale and undercooked while you wonder what went wrong.
Oven temperature is the one conversion that trips up cooks in every country, because there are three competing scales — Fahrenheit, Celsius and gas mark — plus a fan-oven adjustment almost nobody applies correctly. This guide gives you the chart worth trusting, the formula behind it, and the fan-oven rule that quietly ruins bakes. For an instant answer in any direction, the oven temperature converter does all three at once.
The conversion chart
These are the standard cooking values — the rounded numbers real recipes and oven dials actually use, not raw decimal conversions (more on that below). This is the same table behind our converter.
| Description | °C | °F | Gas Mark |
|---|---|---|---|
| Very cool | 120°C | 250°F | ½ |
| Cool | 135°C | 275°F | 1 |
| Cool | 150°C | 300°F | 2 |
| Warm | 165°C | 325°F | 3 |
| Moderate | 180°C | 350°F | 4 |
| Moderately hot | 190°C | 375°F | 5 |
| Fairly hot | 200°C | 400°F | 6 |
| Hot | 220°C | 425°F | 7 |
| Very hot | 230°C | 450°F | 8 |
| Very hot | 245°C | 475°F | 9 |
If you memorise one row, make it the middle one: 180°C = 350°F = gas mark 4, the “moderate oven” most cakes, cookies and casseroles are built around. From there, every gas mark up or down is a 25°F step, which makes the Fahrenheit column easy to reconstruct from memory.
The formula (and why the chart is “rounded”)
Celsius and Fahrenheit convert with one formula:
- Fahrenheit → Celsius: subtract 32, then multiply by 5⁄9.
- Celsius → Fahrenheit: multiply by 9⁄5 (1.8), then add 32.
Run 350°F through it and you get 176.7°C, not 180°C. So why does every chart say 180? Because ovens aren’t precision instruments — most drift ±10–15°C from their dial anyway — so the cooking world standardised on clean, round numbers. 180°C and 350°F are treated as the same setting even though they’re a few degrees apart. For cooking, use the chart values; the small rounding never matters. It only matters if you’re doing something temperature-critical like sugar work or tempering chocolate, where you should trust a probe thermometer over any dial.
Gas mark: where the odd numbers come from
Gas mark is a UK and Ireland scale, and its logic is simpler than it looks. Gas mark 1 is 275°F, and each mark adds exactly 25°F: mark 2 is 300°F, mark 3 is 325°F, and so on up to mark 9 at 475°F. Below 1 the scale halves into ¼ and ½ for slow-cooking and meringue-drying temperatures.
The descriptive words on old recipes map onto it too: a “slow” or “cool” oven is gas mark 1–2, a “moderate” oven is gas mark 4, and a “hot” oven is gas mark 7 and up. If a vintage recipe just says “bake in a hot oven,” reach for about 425°F / 220°C. The oven temperature converter translates a gas mark straight to your dial so you never have to do the 25°F arithmetic in your head.
The fan-oven rule almost everyone gets wrong
Here’s the mistake that turns a good recipe bad: a fan (convection) oven and a conventional oven are not the same temperature. The fan circulates hot air, so food cooks faster and browns harder at the same dial setting. If a recipe was written for a conventional oven and you run it in a fan oven at the stated temperature, the outside overcooks before the inside is done.
The fix is one of two adjustments — pick one, never both:
- Lower the temperature by 20°C (about 25°F, or one gas mark) and keep the time the same. So a recipe’s 180°C becomes 160°C fan. This is the more reliable choice for baking, where even heat matters most.
- Or keep the temperature and cut the time by roughly 25%. Handier for roasts and traybakes where a little extra browning is welcome.
Do both at once and you’ll pull food out underbaked. Note that many modern recipes already state the fan temperature explicitly (look for “fan” or “convection” next to the number) — in that case, no adjustment is needed. Air fryers are just very small, very aggressive fan ovens, which is why they need their own reduction; the air fryer converter handles that per-food.
Quick reference for the temperatures you’ll actually use
- Low and slow (braises, meringues): 120–150°C · 250–300°F · gas ½–2
- Everyday baking (cakes, cookies, casseroles): 180°C · 350°F · gas 4
- Roasting vegetables, bread, pastry: 200–220°C · 400–425°F · gas 6–7
- Blast heat (pizza, searing, crisping skin): 230°C+ · 450°F+ · gas 8+
Beyond temperature
Getting the number right is half the job; the other half is what goes in the oven. If you’re resizing a recipe to a different tin, the cake pan converter tells you how the bake time and volume change — and if you’re switching a recipe from cups to a scale for repeatable results, the cups to grams converter handles 100+ ingredients. Bookmark the oven temperature converter for the moment a recipe and your dial refuse to speak the same language.