How oven temperature conversion works
°C = (°F − 32) × 5/9 and °F = °C × 9/5 + 32 — the exact formulas. Recipes then round to the settings ovens actually have: 350°F works out to 176.7°C but is printed as 180°C, and both are gas mark 4. American recipes use Fahrenheit, European recipes use Celsius, older British recipes use gas marks, and fan (convection) ovens need their own adjustment on top. The chart above runs from "very slow" fruit-cake territory to "very hot" bread and pizza temperatures; the converter takes any number.
Fan oven conversion
Set a fan oven 20°C lower than a conventional recipe — 180°C becomes 160°C fan. That's the UK convention: the Which? conversion table's fan column is 20°C below the conventional one on every row, and Hoover's fan-oven advice says the same. A fan oven isn't hotter than its dial; it cooks faster at the same setting because moving air transfers heat into food faster. 20°C is a 36°F difference.
Going the other way — a recipe that says "180°C fan" and a conventional oven — add 20°C: 200°C, which is 392°F exactly, 400°F on a 25°F dial, gas mark 6. If your oven is a fan oven, a fan recipe needs no change.
US convection ovens follow a separate, smaller rule: makers such as LG say to reduce the recipe by 25°F (about 14°C) for convection bake — 350°F becomes 325°F — and many US ranges subtract it automatically, so check before adjusting twice. Your oven's manual overrides any of these rules of thumb. Changing pan size shifts bake time and temperature too — the cake pan converter works both out from batter depth.
Fan oven conversion chart: fan ↔ conventional ↔ °F ↔ gas mark, both directions →
Common oven conversions at a glance
The temperatures bakers actually search for, one line each — conventional first, fan in brackets (a fan oven cooks faster at the same setting because circulating air transfers heat faster, so set it about 20°C lower):
- 160°C = 325°F = gas mark 3 (fan 140°C) — slow bakes, cheesecakes
- 180°C = 350°F = gas mark 4 (fan 160°C) — the everyday cake temperature
- 190°C = 375°F = gas mark 5 (fan 170°C) — cookies, muffins
- 200°C = 400°F = gas mark 6 (fan 180°C) — breads, choux pastry
- 220°C = 425°F = gas mark 7 (fan 200°C) — pies, high-heat crusts
- 230°C = 450°F = gas mark 8 (fan 210°C) — pizza, lean crusty loaves
Look up a specific temperature
Every standard oven setting has its own page — the exact conversion, the recipe pairing, the fan adjustment in both directions and what bakes there:
°C to °F
°F to °C
How accurate is your oven, really?
A home oven's thermostat cycles the heat on and off around the set point, and many ovens run hot or cold from the factory — which can easily outweigh the few degrees of rounding in the chart above. An inexpensive standalone oven thermometer, placed on the middle rack where the food sits, tells you your oven's true story — and opening the door lets heat out, so peek through the glass instead.
Sources: NIST, SI units – temperature (exact formulas) · Which? oven temperature conversion table (gas marks, fan column) · Hoover UK, fan ovens (−20°C) · LG US, convection cooking (−25°F).