Convection Oven Calculator
Convert oven temperature between conventional (top/bottom heat) and convection (fan), so you hit the right temperature no matter what the recipe uses.
How to use the converter
- Choose which direction you want to convert — from conventional oven to convection, or the other way around.
- Enter the temperature from the recipe in degrees Celsius.
- The calculator shows the converted temperature and a recommended range.
How the conversion is calculated
A convection oven circulates the air with a fan, so heat distributes more evenly and faster around the food than with traditional top/bottom heat. That's why you can usually set the temperature 15–25 °C lower with convection and still get the same result:
Convection → Conventional: Temperature + 20 °C
The calculator uses 20 °C as the main figure, and also shows a recommended range of 5 degrees around it. The exact difference varies somewhat between oven models and brands, so use the range as a general guide.
Why fan ovens cook faster at a lower temperature
In a conventional oven, food is heated mainly by still air and radiation from the elements. A thin layer of cooler air forms around cold food and acts as insulation. The fan blows that layer away and continuously replaces it with hot air, making heat transfer far more effective at the same set temperature.
That is why the temperature is typically reduced by a couple of tens of degrees when a recipe written for conventional heat is used with a fan. The fan also gives a more even temperature throughout the oven, which is the whole point when baking on several shelves at once. On the other hand, for delicate bakes that need to rise slowly, that same airflow can dry the surface too early.
Frequently asked questions
Why can you set a lower temperature with convection?
The convection fan circulates the hot air around the food, so heat transfers faster and more evenly than with conventional top/bottom heat alone. That's why you typically need 15–25 °C less to achieve the same baking or roasting result.
Is 20 degrees always the right difference?
No, 20 °C is a common rule of thumb, but the actual difference can vary between oven brands and models. Check your oven's manual, or test it out the first time you use it.
Should I also adjust the baking time?
The baking time is often a bit shorter with convection due to more even heat distribution, but it varies by dish. Keep an eye on it and use a toothpick test or food thermometer rather than relying blindly on the time in the recipe.