One temperature in, every oven scale out: Fahrenheit, Celsius, Gas Mark, and the lower setting a fan (convection) oven needs.
| Fahrenheit | Celsius | Gas Mark | Fan Celsius | Typical use |
|---|---|---|---|---|
| 275 F | 140 C | 1 | 120 C | Slow roasting, meringues |
| 300 F | 150 C | 2 | 130 C | Slow baking, fruit cakes |
| 325 F | 165 C | 3 | 145 C | Gentle baking |
| 350 F | 175 C | 4 | 155 C | Cakes, cookies |
| 375 F | 190 C | 5 | 170 C | Pastries, roasting |
| 400 F | 200 C | 6 | 180 C | Roast vegetables, bread |
| 425 F | 220 C | 7 | 200 C | Pizza, browning |
| 450 F | 230 C | 8 | 210 C | High-heat roasting |
Fahrenheit and Celsius convert with the standard formula — Celsius = (Fahrenheit - 32) x 5/9. Gas Mark, used on UK gas ovens, rises in regular steps: each whole mark above 1 adds about 25 F (roughly 13-14 C), starting from Gas Mark 1 at 275 F / 140 C. Fan (convection) ovens circulate hot air and cook more efficiently, so recipes written for a conventional oven are usually reduced by 20 C (about 35-40 F) for a fan oven; this converter shows that fan figure alongside the conventional one.
How much lower should a fan oven be set? The standard rule is 20 C lower than the conventional Celsius temperature. If a recipe already states a fan temperature, do not reduce it a second time.
What Gas Mark is 180 C? 180 C is about 350-355 F, which is Gas Mark 4. The nearest marks are the practical answer — home ovens are not precise to a few degrees, and Gas Mark dials include half marks between whole numbers.