Oven Temperature Converter: °F, °C, Gas Marks, Fan Ovens and Your Oven’s Offset

Home › Calculators › Oven Temperature Converter

Opens on Chapter 5’s example: Rafe’s grandmother’s card says “moderate oven, 180°C”.

Temperature

Fan (convection) oven?

My oven runs hot by (°F) a minus number if it runs cool

Altitude (feet)

Load another example from the book

Enter your numbers, then press Work it out.

How it works

The scales start at different zeros (water freezes at 32°F and 0°C) and have different step sizes (180 °F steps against 100 °C steps from freezing to boiling), so converting takes a subtract and a multiply. The shortcut “double it and add 30” is close at room temperature and about 34 degrees too hot at 180°C. Gas mark 1 is 275°F and each mark adds 25°F. Fan-oven advice differs (25°F lower in US manuals, about 20°C lower from UK makers; 20°C is 36°F), so treat it as a starting point. If your oven thermometer reads 15°F above the dial, set the dial 15°F lower. Water boils just under 1°F lower for every 500 feet you climb.

From the book, Chapter 5. 180°C is 356°F (the shortcut says 390, 34 too hot); 425°F is 218.3°C; 350°F is about gas mark 4, and gas mark 6 is 204.4°C. A 375°F recipe in a convection oven: about 350°F; 190°C with the UK fan rule: 338°F. Tamsin sets 385°F to get 400°F. At 5,000 feet water boils 9°F lower, about 95°C. Every chapter and its calculator →

Amounts can be typed as 3, 0.75, 3/4, 1 1/2 or 1½. They’re worked as exact fractions and written as a cook measures them: cups in quarters or thirds, then tablespoons, then teaspoons to the nearest eighth. Everything stays in your browser: no sign-up, nothing stored or sent.