Converting °F, °C and Gas Mark
The formula is simple: °C = (°F − 32) × 5/9, and °F = (°C × 9/5) + 32. But in practice you only need a handful of numbers.
| Fahrenheit | Celsius | Gas Mark | Typical use |
|---|---|---|---|
| 300°F | 150°C | 2 | Slow bakes, meringue |
| 325°F | 160°C | 3 | Cheesecake, rich cakes |
| 350°F | 175°C | 4 | Most cakes & cookies |
| 375°F | 190°C | 5 | Cookies, muffins |
| 400°F | 200°C | 6 | Scones, choux |
| 425°F | 220°C | 7 | Pastry, pizza |
| 450°F | 230°C | 8 | Bread, high-heat roasting |
Fan (convection) ovens: the adjustment everyone forgets
A fan oven circulates hot air, so it cooks faster and browns harder than a conventional oven at the same dial setting.
The universal rule: reduce the temperature by 20°C (about 25°F), or reduce the baking time by roughly 25%. So a recipe calling for 180°C conventional becomes 160°C in a fan oven. Most recipes are written for conventional ovens unless they say otherwise.
Skipping this adjustment is the #1 cause of over-browned edges and dry bakes for people with newer fan ovens. If your cookies always burn at the recommended temperature, this is usually why.
Fan oven help
Your oven is probably lying
Most home ovens are off by 15–25°F (10–15°C), and many have hot spots that bake one side faster than the other. The dial is a suggestion, not a measurement.
- Put a cheap oven thermometer in the center and compare it to the dial after a full preheat.
- Rotate pans halfway through to even out hot spots.
- Always preheat fully — 15–20 minutes — before the food goes in.
For doneness, internal temperature beats the clock: cakes are done at 93–99°C (200–210°F), lean breads at 96–99°C (205–210°F).
The right temperature for what you’re baking
Different bakes want different heat. As a rough map: low and slow for custards and dense cakes, moderate for most cakes and cookies, hot for pastry and bread.
| Bake | Temperature | Why |
|---|---|---|
| Cheesecake, custard | 150–160°C / 300–325°F | Gentle heat prevents cracking and curdling |
| Most cakes | 175°C / 350°F | Balanced rise, moisture and browning |
| Cookies | 175–190°C / 350–375°F | Set edges with a soft center |
| Muffins (for domes) | Start 220°C / 425°F | A hot start forces a tall dome |
| Pastry & pizza | 200–230°C / 400–450°F | High heat for crisp, flaky, fast browning |
| Artisan bread | 230–245°C / 450–475°F | Maximum oven spring and crust |