Oven Temperature Converter

British, American and European kitchens all describe oven heat differently. UK recipes use Celsius (often with a separate fan temperature) or gas marks. American recipes use Fahrenheit. We convert between all four so the recipe you're reading lines up with the dial on your oven.

How the conversion works

Celsius and Fahrenheit are linear: °F = °C × 9⁄5 + 32. Fan ovens circulate hot air, so they cook roughly 20 °C hotter than the dial suggests — to match a conventional oven recipe, drop the temperature by 20 °C. Gas marks are a stepped British scale: gas mark 4 = 180 °C, with each step about 14 °C apart.

A worked example

A recipe says "preheat to 350 °F". That's 175 °C conventional, 155 °C fan, or roughly gas mark 4. Conversely, a UK recipe at 200 °C fan is 220 °C conventional, 425 °F, or gas mark 7 — useful when only your fan setting is broken or your recipe was written for a conventional oven.

Why this matters

Oven temperature is the single biggest variable in baking. Even a 15 °C error can turn a cake claggy in the middle or burn a pastry base before the filling sets. Getting the conversion right — especially between fan and conventional — is the difference between following a recipe and improvising. It also matters for safety: poultry and pork need specific internal temperatures regardless of which units the dial shows.

When to deviate from the recipe

Your own oven probably runs 10–20 °C off the dial — most do. An oven thermometer lets you calibrate. If your bakes routinely brown too fast on top, your oven runs hot; if cakes are pale and undercooked at the recommended time, it runs cool. Adjust the converted temperature accordingly.

Common mistakes

• Using the conventional temperature on a fan oven. Most things will over-brown.
• Treating gas marks as linear. The steps are close to 14 °C apart but never exactly — always check against the table rather than assuming.
• Trusting the oven dial without ever checking with a thermometer.
• Forgetting to preheat fully — most ovens take 15–20 minutes to stabilise, not the 5 the indicator light suggests.

Beyond the numbers

Even at the correct dial setting, ovens cook unevenly. Most have hot spots — typically the back-right corner and the top shelf — that can run 20 °C above the rest of the cavity. That's why professional bakeries rotate their trays mid-bake and why a tray of biscuits often comes out unevenly browned. A cheap oven thermometer placed on the middle shelf is the fastest way to learn how your oven actually behaves; many cookbook authors quietly assume yours is calibrated.

Fan ovens also dry food out faster because the moving air strips moisture from the surface. That's brilliant for roast potatoes and chips; less helpful for delicate sponges, custards or anything cooked in an open dish. When a fan oven gives you trouble, switching to conventional and raising the temperature by 20 °C often rescues the result. Once you've mastered the dial, the Recipe Scaler handles the other half of the equation when batch size changes.

Related tools: Cups to Grams, Grams to Cups, Butter Conversion, and the Recipe Scaler.