Oven Temperature Conversion Guide: Celsius, Fahrenheit, Fan and Gas Mark

5 min read · Updated October 20, 2026 · By Mohammad Dawood Edris Ghanizada

Oven temperature is one of the easiest things to get wrong when you follow a recipe from another country. The temperature scale may differ, the oven type may differ, and even the numbers on your dial may not match what is happening inside. This guide covers the conversions you need.

The formulas

• Celsius to Fahrenheit: °F = °C × 9/5 + 32
• Fahrenheit to Celsius: °C = (°F − 32) × 5/9

Most recipes round the results to the nearest 5 or 10 degrees, since ovens are not that precise.

Common oven settings

Fan (convection) ovens

A fan circulates hot air, which cooks food faster and more evenly. As a general rule, reduce the temperature by about 20°C (or 25°F) compared with a conventional oven, or shorten the cooking time by roughly 10 to 15 percent. Many UK recipes list both: for example "180°C / 160°C fan". If a recipe does not say which oven it was written for, assume conventional.

Your oven may be lying

Home ovens are often off by 10 to 25 degrees. An inexpensive oven thermometer placed on the middle rack tells you the real temperature. If your oven consistently runs hot or cold, adjust the dial accordingly. This is often the real reason a trusted recipe suddenly "stops working" in a new kitchen.

Positioning and preheating

• Preheat for at least 15 to 20 minutes. The beep usually signals the air is hot, not that the walls have stabilised.
• Bake most cakes and cookies on the middle rack.
• Use the upper rack for browning and the lower rack for crisp bases such as pizza or pies.
• Avoid opening the door in the first half of baking, because each opening can drop the temperature by 15°C or more.

Quick tool

For any other value, use the Celsius to Fahrenheit converter or the Fahrenheit to Celsius converter.