Gas Mark conversion
Gas Mark 1 in °C & °F
Gas Mark 1 is 140°C or 275°F, a cool oven. In a fan oven, use 120°C.
Gas Mark 1 equals
140°C
275°F · exactly 135°C
What Gas Mark 1 is used for
Cool
Gas Mark 1 is a cool oven at 140°C (275°F). It is used for slow roasts and long, gentle bakes.
Why charts differ slightly
From Gas Mark 1 upwards, each mark is 25°F hotter than the one before, starting at 275°F. Gas Mark 1 is 275°F, which is exactly 135°C. UK recipe charts round this to the nearest 10°C oven setting, which gives 140°C. Small differences between charts (for example 160°C or 170°C for Gas Mark 3) come from that rounding, and they rarely matter in practice.
Gas ovens are hotter near the top than at the bottom, so the gas mark is meant for the middle shelf. Fan ovens heat more evenly, which is why they need a lower setting.
Convert another temperature
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All gas marks
| Gas Mark | °C | °F | Fan °C |
|---|---|---|---|
| Gas Mark ¼ | 110°C | 225°F | 90°C |
| Gas Mark ½ | 120°C | 250°F | 100°C |
| Gas Mark 1 | 140°C | 275°F | 120°C |
| Gas Mark 2 | 150°C | 300°F | 130°C |
| Gas Mark 3 | 160°C | 325°F | 140°C |
| Gas Mark 4 | 180°C | 350°F | 160°C |
| Gas Mark 5 | 190°C | 375°F | 170°C |
| Gas Mark 6 | 200°C | 400°F | 180°C |
| Gas Mark 7 | 220°C | 425°F | 200°C |
| Gas Mark 8 | 230°C | 450°F | 210°C |
| Gas Mark 9 | 240°C | 475°F | 220°C |
See the full gas mark chart with exact values, or print the whole conversion chart.
Common questions
What temperature is Gas Mark 1?
Gas Mark 1 is 140°C or 275°F (exactly 135°C).
What is Gas Mark 1 in a fan oven?
Use 120°C in a fan oven, which is 20°C below the conventional 140°C.
What is Gas Mark 1 in Fahrenheit?
Gas Mark 1 is 275°F. Gas marks were defined in Fahrenheit, so this is the exact figure.
Is Gas Mark the same on every gas oven?
The scale is standard, but individual ovens vary, and gas ovens are hotter at the top than the bottom. Cook on the middle shelf, and use an oven thermometer if your results are often off.