Oven Temperature Converter — °F, °C, Gas Mark
Convert oven temperatures between Fahrenheit (°F), Celsius (°C), and the UK Gas Mark scale. Includes fan-oven adjustment (subtract 20 °C / 25 °F) and verbal descriptions (cool, moderate, hot, very hot). Essential for using US recipes in UK kitchens and vice versa.
Convert temperature
How to Use This Oven Temperature Converter
- Enter a temperature in any one of the three fields — Fahrenheit, Celsius, or Gas Mark. The others update automatically.
- Choose Conventional or Fan oven to see the equivalent for the other type.
- Read the verbal description (cool, moderate, hot) — useful when a recipe says "moderate oven" with no number.
Conversion Formula and Method
Fahrenheit ↔ Celsius: °C = (°F − 32) × 5/9. °F = °C × 9/5 + 32.
Celsius ↔ Gas Mark: The UK Gas Mark scale is non-linear and predates the standard Celsius oven dial. The widely-used conversion is:
- Gas Mark ¼ = 110 °C / 225 °F (very cool)
- Gas Mark ½ = 120 °C / 250 °F
- Gas Mark 1 = 140 °C / 275 °F (cool)
- Gas Mark 2 = 150 °C / 300 °F
- Gas Mark 3 = 170 °C / 325 °F (warm)
- Gas Mark 4 = 180 °C / 350 °F (moderate)
- Gas Mark 5 = 190 °C / 375 °F
- Gas Mark 6 = 200 °C / 400 °F (fairly hot)
- Gas Mark 7 = 220 °C / 425 °F (hot)
- Gas Mark 8 = 230 °C / 450 °F (very hot)
- Gas Mark 9 = 240 °C / 475 °F
Fan-oven adjustment: reduce conventional temperature by 20 °C (or 25–30 °F) when using a fan oven, because circulating air transfers heat more efficiently. Bakers often also reduce time by 10–15%.
Worked Example — UK Recipe in a US Oven
A British recipe says "bake at Gas Mark 6 for 25 minutes."
- Gas Mark 6 = 200 °C / 400 °F.
- US oven without fan: set to 400 °F. Same time.
- US oven with convection fan: set to 375 °F (200 °C − 20 °C = 180 °C, then × 9/5 + 32 = 356 °F, round to 375 °F).
Worked Example — US Recipe in a UK Fan Oven
A US recipe says "bake at 375 °F for 30 minutes."
- 375 °F → 190 °C (Gas Mark 5).
- UK fan oven: subtract 20 °C → set to 170 °C / Gas Mark 3.
- Check at 25–27 minutes (10–15% shorter time).
Oven Temperature Reference Table
| Description | °F | °C (conv) | °C (fan) | Gas Mark |
|---|---|---|---|---|
| Very cool | 225–250 | 110–120 | 90–100 | ¼–½ |
| Cool | 275 | 140 | 120 | 1 |
| Slow | 300 | 150 | 130 | 2 |
| Warm | 325 | 170 | 150 | 3 |
| Moderate | 350 | 180 | 160 | 4 |
| Moderately hot | 375 | 190 | 170 | 5 |
| Fairly hot | 400 | 200 | 180 | 6 |
| Hot | 425 | 220 | 200 | 7 |
| Very hot | 450 | 230 | 210 | 8 |
| Extremely hot | 475 | 240 | 220 | 9 |
Common Cooking Scenarios
Roasting meat
Most meats roast at 180 °C / 350 °F / Gas Mark 4 (moderate) for slow roasting, or 200 °C / 400 °F / Gas Mark 6 for browner crusts. Fan oven: 160 °C and 180 °C respectively. Use a meat thermometer for doneness — temperatures matter less than internal core temperature.
Baking bread
Most bread bakes at 220 °C / 425 °F / Gas Mark 7. Sourdough often goes higher (240 °C / 475 °F / Gas Mark 9) with steam in the first 10 minutes. Fan oven: 200 °C / 220 °C respectively.
Cakes and biscuits
Most cakes: 170 °C / 325 °F / Gas Mark 3 (warm-moderate). Fan: 150 °C. Biscuits: 180 °C / 350 °F / Gas Mark 4. Sponges and meringues use lower temperatures (140–150 °C) to prevent over-browning.
Frozen pizza / convenience food
Most packaging gives a conventional temperature (e.g., 200 °C). For fan ovens, reduce by 20 °C. Watch carefully — the high airflow of a fan oven can over-crisp the base before the topping is properly hot.
Slow-cooking / low-and-slow
120 °C / 250 °F / Gas Mark ½ for pulled pork, beef brisket, or pulled lamb shoulder (6–10 hours). Fan oven: 100 °C — but most ovens struggle to hold below 130 °C reliably; check with a separate oven thermometer.
Tips and Considerations
- Most ovens run 10–25 °C off the dial reading. Buy a separate oven thermometer — it pays for itself the first time a cake doesn't burn.
- Fan oven = ~20 °C lower. Some manufacturers say 25 °C — check your manual. Modern fan-assist (not full fan) ovens can be in between.
- Don't open the door. Each opening drops the temperature 15–25 °C. Use the oven light for checking.
- Preheat fully. 10–15 minutes is the safe minimum. The dial reaching temperature does not mean the oven walls have reached it.
- Aga / Rayburn cooking. Aga roasting oven runs 230–250 °C; baking oven 180–200 °C; simmering oven 130–150 °C; warming oven 80–100 °C. Direct gas mark conversion doesn't apply — use the Aga zones instead.
- Pizza stone effect. A pizza stone or steel adds 10–20 °C effective baking temperature by storing and radiating heat. Preheat 30+ minutes.
Related Calculators
- Conversion Calculator — all unit conversions.
- Unit Converter — length, weight, volume, temperature.
- Stones & Pounds to Kg — for recipe weights.
Sources & References
- UK Gas Mark scale — standardised by British Gas in the 1960s for domestic ovens.
- BBC Good Food — oven temperature guide.
- NIST — Celsius/Fahrenheit conversion formulas.
Frequently Asked Questions
What is 180 °C in Fahrenheit?
180 °C = 356 °F (commonly rounded to 350 °F in recipes). Gas Mark 4 (moderate oven).
What is Gas Mark 4?
180 °C / 350 °F — a moderate oven. The most-used setting for many baked dishes, cakes, and roasts.
How do I convert °F to °C?
Subtract 32, then multiply by 5/9. Quick approximation: subtract 30, then halve.
Why does fan oven need lower temperature?
The fan circulates hot air faster than convection currents alone, transferring heat more efficiently. The dial temperature in a fan oven represents the air temperature, but food cooks faster, so you reduce by ~20 °C to compensate.
Is Gas Mark used outside the UK?
Mostly UK and Ireland. Continental Europe uses °C. The US uses °F. Older UK gas ovens often only have Gas Mark dials with no Celsius.
What is 350 °F in Gas Mark?
Gas Mark 4 (180 °C). The single most common American baking temperature.
Does the oven type affect cooking time?
Yes. Fan ovens typically cook 10–15% faster at the same temperature. Modern fan-assist (combi) ovens are between conventional and full-fan in behaviour.
Last reviewed: 18 May 2026. Gas Mark conversion follows the standard British Gas scale. Always preheat fully and use a separate oven thermometer for critical bakes.