Oven Temperature Converter

Convert oven temperatures between °C, °F and gas mark.

Free oven temperature converter for Celsius, Fahrenheit and gas mark, with a fan-oven note. Runs entirely in your browser — nothing is uploaded. It runs free in your browser on Gera Tools, with nothing uploaded.

Last updated Source: Gera Tools

How do I convert a conventional oven temperature for a fan oven?

As a rule of thumb, set a fan (convection) oven about 20 °C lower than the conventional temperature shown, since fans circulate heat more efficiently.

Recipes from different countries quote oven temperatures in Celsius, Fahrenheit or UK gas marks, which makes following them awkward. This converter shows all three side by side: enter a temperature in any one unit and the equivalents update instantly, with a reminder to drop fan-oven settings by about 20 °C.

How it works

Celsius and Fahrenheit convert with the exact formulas °F = °C × 1.8 + 32 and °C = (°F − 32) ÷ 1.8. Gas mark is not a linear scale, so it uses the standard UK reference table — when you enter a Celsius or Fahrenheit value, the tool picks the closest gas mark by temperature; when you pick a gas mark, it reads off its fixed Celsius value and converts to Fahrenheit.

Complete gas mark reference table

Gas markCelsiusFahrenheitCommon use
1/4110 °C225 °FVery slow / warming
1/2120 °C250 °FSlow / meringues
1140 °C275 °FSlow cook / braising
2150 °C300 °FSlow cook / rich fruit cake
3160 °C325 °FModerately slow / casseroles
4180 °C350 °FModerate / most cakes, biscuits
5190 °C375 °FModerately hot / pastry
6200 °C400 °FHot / roast vegetables, bread rolls
7220 °C425 °FHot / roast potatoes, puff pastry
8230 °C450 °FVery hot / pizza, searing
9240 °C475 °FExtremely hot / flatbreads

Fan oven adjustment

Fan-assisted (convection) ovens circulate hot air, which makes them cook more efficiently. The rule of thumb is to set the fan oven 20 °C lower than the conventional temperature given in the recipe, or reduce cooking time by roughly 10 minutes per hour. Some recipes and appliance manuals quote 25 °C lower — if in doubt, check your oven’s manual.

For example: a recipe calling for 200 °C in a conventional oven becomes approximately 180 °C in a fan oven, which is also gas mark 4. This is useful to know because many older British and American recipes predate fan ovens and quote conventional temperatures throughout.

Worked example

Enter 180 °C:

  • Fahrenheit = 180 × 1.8 + 32 = 356 °F (commonly rounded to 350 °F)
  • Closest gas mark = 4
  • For a fan oven, set roughly 160 °C instead

Common baking temperatures at a glance

  • Cheesecake, slow roasting: 140–150 °C (gas 1–2)
  • Victoria sponge, most sponge cakes: 170–180 °C (gas 3–4)
  • Shortcrust pastry, roast chicken: 190–200 °C (gas 5–6)
  • Roast potatoes, pizza base: 220–230 °C (gas 7–8)
  • Bread (initial blast heat): 230–240 °C (gas 8–9)

Everything runs in your browser — no uploads, no tracking.