Oven temperatures · gas mark guide
Gas Mark 3 in °C, fan and °F
Gas Mark 3 is 170°C in a conventional electric oven, 150°C in a fan oven and 325°F. It is a low oven, the usual setting for casseroles, shortbread and slower-baked cakes.
Chart checked against Delia Smith and Waitrose on .
Conventional oven
170°C
electric, no fan
Fan oven
150°C
20°C lower
Fahrenheit
325°F
exactly 163°C
Heat
Low
gas mark 3
Gas Mark 3 and the settings either side
Conventional and fan temperatures in °C, with °F for American recipes.
| Gas mark | Conventional | Fan | Fahrenheit | Heat |
|---|---|---|---|---|
| Gas 1 | 140°C | 120°C | 275°F | Very low |
| Gas 2 | 150°C | 130°C | 300°F | Very low |
| Gas 3 | 170°C | 150°C | 325°F | Low |
| Gas 4 | 180°C | 160°C | 350°F | Moderate |
| Gas 5 | 190°C | 170°C | 375°F | Moderately hot |
Fan ovens
If your electric oven has a fan you cannot switch off, set it to 150°C instead of 170°C. Delia Smith's advice is to take 20°C off conventional temperatures, or check your oven's handbook, as some models run hotter than others.
Why the numbers are rounded
325°F is exactly 162.8°C. Recipe charts round it to 170°C because ovens are not accurate to a few degrees anyway. An oven thermometer is the best way to know what your oven is really doing.
Some charts say 160°C
Gas mark 3 is the one setting charts disagree on. Delia Smith lists it as 170°C and 325°F, while Waitrose lists 160°C and 320°F. 325°F is 163°C, so either works for most recipes; use 160°C if a cake tends to brown before the middle is cooked.
Related conversions
- Gas mark 2 (150°C · 300°F)
- Gas mark 4 (180°C · 350°F)
- 170°C to gas mark (conventional and fan)
- 325°F to gas mark (US recipes)
Common questions
What is Gas Mark 3 in Celsius?
170°C in a conventional oven, or 150°C if your oven has a fan.
What is Gas Mark 3 in a fan oven?
150°C. Fan ovens cook faster because the fan moves hot air around the food, so set them about 20°C lower than a conventional oven.
What is Gas Mark 3 in Fahrenheit?
325°F. That is the figure American recipes use for a low oven.
What do you cook at Gas Mark 3?
Casseroles, shortbread and slower-baked cakes.
Sources and assumptions
- Conventional means an electric oven with the fan off. Fan settings are 20°C lower.
- Recipe charts round temperatures to the nearest 10°C or 25°F, so exact conversions differ by a few degrees.
- Delia Smith: oven temperatures and conversions (gas marks 1 to 9, fan ovens)
- Waitrose: conversion charts (gas marks ¼ and ½)
Ovens vary. An oven thermometer shows what yours is really doing.