Gas Mark ½ temperature
Gas Mark ½ is 120°C (250°F) — very cool. In a fan oven, set about 100°C.
Fan (convection) ovens run about 20°C cooler than conventional for the same result — so set the fan oven to 100°C. Gas Mark values are standard oven-dial settings (very cool).
Oven temperature chart (°C · °F · Gas Mark · Fan)
| °C | °F | Gas Mark | Fan °C | Description |
|---|---|---|---|---|
| 110° | 225° | ¼ | 90° | Very cool / slow |
| 120° | 250° | ½ | 100° | Very cool |
| 140° | 275° | 1 | 120° | Cool |
| 150° | 300° | 2 | 130° | Cool |
| 170° | 325° | 3 | 150° | Warm |
| 180° | 350° | 4 | 160° | Moderate (most baking) |
| 190° | 375° | 5 | 170° | Moderately hot |
| 200° | 400° | 6 | 180° | Fairly hot |
| 220° | 425° | 7 | 200° | Hot |
| 230° | 450° | 8 | 210° | Very hot |
| 240° | 475° | 9 | 220° | Very hot |
Gas Mark and the °F column are standard oven-dial settings (rounded). Exact math: °F = °C × 9/5 + 32 (so 180°C = 356°F exactly, set to 350°F on the dial).
FAQ
180°C = 350°F = Gas Mark 4 — the most common baking temperature. In a fan oven, set it to about 160°C.
Lower the temperature by about 20°C (fan ovens circulate hot air, so they cook faster and more evenly). Some recipes also shorten the time slightly. When unsure, check 5–10 minutes early.
Mathematically 180°C is 356°F, but oven dials and recipes use rounded "standard" settings, so 180°C is written as 350°F. The small difference doesn't matter for cooking.
Gas Mark is the dial scale on UK gas ovens. Each mark is a set temperature: Gas Mark 1 = 140°C/275°F, and each step up adds roughly 10–20°C. Gas Mark 4 (180°C) is the everyday baking setting.