Gas mark 1
140°C · 275°F · 120°C fan
Cool oven — slow-cooked casseroles, rich fruit cake.
Gas mark 1 in every scale
| Gas mark | 1 |
| Fahrenheit | 275°F (exact — gas mark 1 is defined as this) |
| Celsius, conventional oven | 140°C (the arithmetic conversion is 135.0°C; recipes round it) |
| Celsius, fan oven | 120°C |
| Fahrenheit, fan oven | 248°F |
| Description | Cool |
Frequently asked questions
What is gas mark 1 in Celsius?
140°C in a conventional oven, or 120°C in a fan oven.
What is gas mark 1 in Fahrenheit?
275°F, exactly — gas mark 1 is defined as 275°F.
Why is gas mark 1 called 140°C when 275°F is 135.0°C?
Because 135.0°C is not a number an oven dial can be set to. Recipes round to the nearest ten, and the rounded figure is the convention everywhere — the 5.0 degree difference is well inside the accuracy of a domestic thermostat.
What is gas mark 1 used for?
Cool — slow-cooked casseroles, rich fruit cake.
The settings either side
| Gas mark | Fahrenheit | Celsius | Fan / convection | |
|---|---|---|---|---|
| 1/2 | 250°F | 130°C | 110°C fan | Very cool |
| 1 | 275°F | 140°C | 120°C fan | Cool |
| 2 | 300°F | 150°C | 130°C fan | Cool |
The full chart, and why the three scales disagree →
All oven temperatures · 140°C to °F precisely · Cooking measurements