Oven Temperature Guide: Celsius, Fahrenheit, and Gas Mark Conversion Chart
You found a great recipe — but it says "bake at Gas Mark 6" and your oven only shows Fahrenheit. Or it says 200°C and you're staring at an American dial that maxes out at 550°F. This is the guide that fixes that, once and for all.
This article is part of our complete pillar guide on Temperature Scales: The Complete Guide. For instant lookups while cooking, jump to our Oven Temperature Converter, or use the general-purpose Temperature Converter for non-cooking conversions. You may also want to read Celsius vs Fahrenheit and Kelvin Scale Explained for the science behind the scales.
Why Oven Temperatures Vary by Country
Three things have to line up before two cooks in two countries can talk about heat: the temperature scale, the oven type (gas vs electric, fan vs conventional), and the labeling convention.
In the United States, ovens are calibrated in Fahrenheit. Dials run from about 200°F to 550°F.
In most of Europe, Australia, and Asia, electric ovens use Celsius — typically 50°C to 250°C.
In the United Kingdom and Ireland, things get interesting. Older gas ovens use the Gas Mark scale, which goes from ¼ (the coolest setting) up to 9 (hottest). The scale dates to the 1940s, when British gas companies standardized markings on cookers. Each Gas Mark increment corresponds to roughly 25°F (14°C).
Recipe books from before the 1990s often use phrases like "a moderate oven" or "a hot oven" — vague but useful when you knew your own cooker. We've included those descriptors in the table below.
💡 Fun fact: Gas Marks were standardized by the British Gas Standards Board in the 1940s because gas ovens couldn't accurately go below 240°F at the time.
The Master Conversion Chart
Here's the conversion table you'll actually use. Save it, print it, or pin it next to your stove.
| Celsius | Fahrenheit | Gas Mark | Description | Common Use |
|---|---|---|---|---|
| 110 °C | 225 °F | ¼ | Very Slow | Meringues, drying herbs |
| 120 °C | 250 °F | ½ | Very Slow | Pavlova, slow drying |
| 140 °C | 275 °F | 1 | Slow / Cool | Slow-cooked stews, rich fruit cakes |
| 150 °C | 300 °F | 2 | Slow | Low and slow braises |
| 160 °C | 325 °F | 3 | Moderately Slow | Custards, cheesecake |
| 170 °C | 340 °F | 3 | Moderate | Pound cake, sponges |
| 180 °C | 350 °F | 4 | Moderate | Standard baking — cookies, cakes, brownies |
| 190 °C | 375 °F | 5 | Moderately Hot | Muffins, quick breads, pies |
| 200 °C | 400 °F | 6 | Hot | Roasted vegetables, scones, pastry |
| 220 °C | 425 °F | 7 | Hot | Roast meats, choux pastry |
| 230 °C | 450 °F | 8 | Very Hot | Bread, pizza, puff pastry |
| 240 °C | 475 °F | 9 | Extremely Hot | Crusty artisan bread, searing |
| 260 °C+ | 500 °F+ | — | Maximum | Pizza stone, broiling |
Conversion Formulas
If you ever get caught without a chart, the formulas are simple.
Celsius to Fahrenheit:
- °F = (°C × 9/5) + 32
Fahrenheit to Celsius:
- °C = (°F − 32) × 5/9
Gas Mark to Fahrenheit:
- °F = (Gas Mark × 25) + 250 (approximate, valid from Gas Mark 1 upward)
Fahrenheit to Gas Mark:
- Gas Mark = (°F − 250) / 25
Example: 400°F → Gas Mark = (400 − 250) / 25 = 6. Checks out.
Fan Oven vs Conventional Oven
This is the single most common reason a baking recipe goes wrong. A fan-assisted (convection) oven circulates hot air, which cooks food faster and more evenly than a conventional radiant oven.
The rule of thumb is to reduce the temperature by 20°C (or about 25°F) when using a fan oven, or alternatively reduce cooking time by about 25%.
💡 Fun fact: Convection (fan) ovens cook about 20°C / 25°F faster than conventional ovens because moving air strips away the insulating cold layer right next to the food.
| Conventional | Fan Oven |
|---|---|
| 160 °C / 325 °F | 140 °C / 275 °F |
| 180 °C / 350 °F | 160 °C / 325 °F |
| 200 °C / 400 °F | 180 °C / 350 °F |
| 220 °C / 425 °F | 200 °C / 400 °F |
If a recipe doesn't specify, assume conventional. British and Australian recipes usually note "fan" or "(fan 160°C)" alongside the main temperature. American recipes almost always assume conventional unless they explicitly say "convection."
Common Baking Applications
Different foods need different heat for very different reasons — moisture management, crust development, browning chemistry.
Bread
Most yeasted bread bakes at 220-240°C / 425-475°F / Gas 7-9. The high initial heat triggers "oven spring" — a final burst of expansion as the yeast dies and gases expand. Sourdough loaves often start at 240°C with steam, then drop to 220°C after 20 minutes for the crust to set without burning.
Cookies
180-190°C / 350-375°F / Gas 4-5 is the sweet spot. Too low and they spread into greasy puddles before setting. Too high and the edges burn before the centers cook.
Pizza
Pizza wants the highest heat your oven can deliver — 240°C / 475°F / Gas 9 is the minimum, and most pizzaiolos crank it to 260°C / 500°F or higher with a pizza stone preheated for at least 45 minutes. Neapolitan wood-fired ovens hit 480°C (900°F) and cook a pizza in 90 seconds.
💡 Fun fact: Wood-fired pizza ovens regularly hit 900°F+ (480°C+). A standard home oven tops out at around 550°F (290°C), which is why store-bought pizza rarely matches a real pizzeria.
Roasting Meat
A two-stage approach works best. Sear at 220°C / 425°F / Gas 7 for 15-20 minutes to develop a crust, then drop to 160-170°C / 325-340°F / Gas 3 for the remainder. Use a meat thermometer — internal temperature beats clock time every time.
Troubleshooting
A few common problems and how to fix them.
- Cookies burning on the bottom but raw on top — your oven runs hot on the bottom element, or you're using a dark/thin baking sheet. Drop temperature by 10°C, move the rack up, and use a doubled-up sheet.
- Bread that doesn't rise (no "oven spring") — oven not preheated long enough, or temperature too low. Bread needs that initial blast at 220°C+. Preheat for at least 30 minutes with the rack and baking stone in place.
- Cakes that sink in the middle — oven too hot, causing the outside to set while the inside is still rising. Drop temperature by 10-20°C and check with a skewer at the earliest end of the suggested time.
- Roast vegetables that steam instead of caramelize — pan overcrowded or temperature too low. Use 220°C / 425°F minimum, spread vegetables in a single layer, give them room.
Key Takeaways
- Standard baking temperature worldwide is 180°C / 350°F / Gas Mark 4.
- Each Gas Mark step equals about 25°F or 14°C.
- For fan ovens, subtract 20°C (25°F) from any conventional recipe temperature.
- Oven thermometers cost £8/$10 and reveal that most home ovens are 10-20°C off the dial setting. If your baking is inconsistent, this is the first thing to check.
FAQ
What's Gas Mark 4 in Celsius?
Gas Mark 4 is approximately 180°C or 350°F. This is the most common baking temperature and the default for cakes, cookies, and casseroles.
Should I always reduce temperature for a fan oven?
For baking and roasting, yes — reduce by 20°C (25°F) or shorten the time by about 25%. For high-heat tasks like searing meat or crisping pizza, you can leave the temperature unchanged because the recipe is already at or near the maximum.
Why does my oven temperature seem inaccurate?
Most domestic ovens drift 10-20°C from their set temperature, and many cycle on and off rather than holding steady. A separate oven thermometer placed on the middle rack will tell you the true temperature. Recalibration is possible on most modern models via the settings menu.
Can I convert microwave wattage to oven temperature?
No — these are fundamentally different cooking methods. Microwaves heat by exciting water molecules; ovens heat by radiation and convection. There's no meaningful conversion. Recipes designed for one cannot be timed-converted to the other.
What does "preheat fully" mean?
The oven indicator light usually turns off long before the oven is truly heat-soaked. Allow at least 15 minutes after the light goes off for the oven walls, racks, and any stones inside to reach temperature. For bread and pizza, give it 30-45 minutes.