How Oven Temperature Conversion Works
Recipes travel across borders, but ovens don't. An American recipe gives you Fahrenheit, a French one Celsius, and a classic British cookbook a gas mark. Get the conversion wrong and your cake either sinks in the middle or burns on top. The math itself is simple — the hard part is remembering it mid-recipe with floury hands.
°F = °C × 9 / 5 + 32
Gas Mark = (°F − 250) / 25
The gas mark scale is the one that trips people up. It's linear: gas mark 1 equals 275°F (140°C), and every step up adds 25°F. That's why gas mark 4 lands neatly on the universal baking temperature of 350°F.
Worked Example
Say a recipe calls for 350°F and your oven only shows Celsius and a fan symbol:
- Conventional Celsius: (350 − 32) × 5 / 9 = 176.6°C → 175°C
- Fan / convection: 175 − 20 = 155°C (or keep 175°C and cut time ~20%)
- Gas mark: (350 − 250) / 25 = gas mark 4
One input, every setting you might need — that's the whole point of the converter above.
Common Oven Temperatures at a Glance
- 275°F / 140°C / Gas 1 — meringues, slow braises, dehydrating
- 325°F / 160°C / Gas 3 — cheesecakes, custards, low roasts
- 350°F / 180°C / Gas 4 — cakes, cookies, casseroles (the default)
- 400°F / 200°C / Gas 6 — roast vegetables, pies, scones
- 425°F / 220°C / Gas 7 — pizza, roast potatoes, quick-roast chicken
- 450°F / 230°C / Gas 8 — bread crust, high-heat searing
Practical Tips for Accurate Oven Temperatures
- Use an oven thermometer. Most home ovens are off by 15–25°F. A cheap dial thermometer tells you what's really happening inside.
- Preheat fully. The "ready" beep often fires before the oven walls are actually at temperature. Add 5–10 minutes for baking-critical recipes.
- Adjust for fan ovens. If your recipe assumes a conventional oven and yours is a fan model, drop 20°C or watch the clock closely.
- Round sensibly. A couple of degrees never ruined a roast. Use the nearest mark your dial supports.
Oven Temperature Converter FAQ
How do I convert Fahrenheit to Celsius for the oven?
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. For example, 350°F becomes (350 − 32) × 5/9 = 176.6°C, which most ovens round to 175°C. The reverse formula is Celsius × 9/5 + 32. This calculator does both directions and rounds to the nearest standard oven dial setting for you.
What is gas mark 4 in Fahrenheit and Celsius?
Gas mark 4 is 350°F (180°C), the most common baking temperature. The UK gas mark scale starts at gas mark 1 = 275°F (140°C) and rises by 25°F per mark. So gas mark 6 is 400°F (200°C) and gas mark 8 is 450°F (230°C). This is why so many British recipes specify gas mark 4 for cakes and roasts.
Do I lower the temperature for a fan or convection oven?
Yes. A fan (convection) oven circulates hot air, so it cooks faster and more evenly. The standard rule is to reduce the conventional temperature by about 20°C (roughly 25–35°F), or keep the temperature the same and cut the cooking time by about 20%. This calculator shows the fan-adjusted Celsius temperature automatically.
Why does 350°F convert to 176°C but recipes say 180°C?
The exact math gives 176.6°C, but oven dials and recipe writers round to convenient marks. 350°F is treated as 175°C or 180°C interchangeably in practice — the few degrees of difference are well within the swing of a typical home oven thermostat. Use 180°C when your dial only has 10-degree increments.
What is the most common oven temperature for baking?
350°F (175–180°C, gas mark 4) is the default for most cakes, cookies, and casseroles because it bakes the interior through before the outside over-browns. Roasting often uses 400–425°F (200–220°C) for a crisp exterior, while low-and-slow braises and meringues sit around 275–325°F (140–160°C).