Temperature
Celsius, Fahrenheit, and the British gas mark.
| Description | °C | °F | Gas |
|---|---|---|---|
| Very cool — meringues, drying | 110°C | 225°F | ¼ |
| Cool — slow-cooked stews, custards | 140°C | 275°F | 1 |
| Warm — fruitcakes, low-and-slow bakes | 150°C | 300°F | 2 |
| Moderate — most cakes, cookies | 175°C | 350°F | 4 |
| Moderately hot — bread, pies | 190°C | 375°F | 5 |
| Hot — roasts, pastry, pizza | 200°C | 400°F | 6 |
| Very hot — high-heat searing | 230°C | 450°F | 8 |
Recipes published in different countries assume different oven labels, and the mismatch leads to small but consequential errors. A Fahrenheit oven set to 350° is the workhorse of American baking; the same oven written up in a British cookbook would read “moderate, gas mark 4”; the same oven in a French cookbook would read 175 °C. The conversion isn't hard, but it's easy to fumble at the edges of the gas-mark scale.
How the conversions work
Celsius and Fahrenheit are both linear scales offset against each other. The exact formula is:
°F = (°C × 9 / 5) + 32, and °C = (°F − 32) × 5 / 9
Gas marks are a stepped scale used by British and Irish gas ovens. Each mark corresponds to a specific temperature range, with rough increments of 25 °F (about 14 °C) per mark. The widely accepted equivalents:
- Gas ¼ — 110 °C / 225 °F — very cool, for meringues and slow drying
- Gas ½ — 130 °C / 250 °F — very cool, for pavlovas
- Gas 1 — 140 °C / 275 °F — cool
- Gas 2 — 150 °C / 300 °F — cool, for stews and custards
- Gas 3 — 165 °C / 325 °F — warm, for fruitcakes and rich pastry
- Gas 4 — 175 °C / 350 °F — moderate, the universal cookie/cake setting
- Gas 5 — 190 °C / 375 °F — moderate
- Gas 6 — 200 °C / 400 °F — moderately hot, for bread and pies
- Gas 7 — 220 °C / 425 °F — hot, for roasts and pastry
- Gas 8 — 230 °C / 450 °F — hot, for pizza
- Gas 9 — 245 °C / 475 °F — very hot, for high-heat searing
Conventional vs. fan ovens
Most published recipes assume a conventional (non-fan) oven. If your oven has a fan (sometimes called convection or fan-assisted), the airflow circulates heat more efficiently, and the rule of thumb is: reduce the recipe temperature by about 20 °C (or 25–30 °F), or shorten the cooking time by about 10–15%, but not both. So a recipe calling for 180 °C in a conventional oven becomes about 160 °C in a fan oven.
Why your oven probably lies
Domestic ovens are notoriously inaccurate. Most are calibrated for the centre of the chamber and run hotter or cooler at the rack positions you actually use; many drift over time. The single most useful kitchen accessory you can buy after a digital scale is an oven thermometer: a small mercury or bimetallic gauge you sit on the shelf alongside whatever you're cooking. Once you know your oven runs 15 °C hot on the middle rack, you compensate automatically.
Recipe scaling and temperature
When you scale a recipe up or down, the oven temperature usually stays the same — but the cooking time changes, sometimes by a lot. A doubled cake doesn't bake at higher heat; it bakes at the same heat for longer, because the centre takes longer to reach doneness. For estimates of how time changes, see the cooking-time guide. If you're also switching to a smaller pan, the batter will be deeper and may need a 10–25 °C reduction to keep the edges from over-baking before the centre sets — see the pan-size converter.
Other converters