Oven temperature converter

Converting oven temperatures without the guesswork

I cook from recipes written all over the world, so my kitchen runs into this constantly: a Korean baking blog lists a temperature in Celsius, an old British recipe calls for "gas mark 6," and my own oven only speaks Fahrenheit. Rather than scribble conversions on a sticky note every time, I made this little converter so I can move between Fahrenheit, Celsius, and gas mark in one place. Pop in whatever number your recipe gives you and it'll hand back the others.

If you'd rather understand the math (and avoid a too-hot or too-cool oven), here's everything I wish someone had explained to me when I started baking.

Fahrenheit, Celsius, and how they line up

The formula itself is simple. To go from Celsius to Fahrenheit, multiply by 9, divide by 5, and add 32. To go the other way, subtract 32, multiply by 5, and divide by 9. In practice, a few oven temperatures come up so often that they're worth keeping in your head:

• 325°F is about 160°C — gentle, for custards and slow bakes
• 350°F is about 175–180°C — the everyday baking temperature for cookies, cakes, and most casseroles
• 375°F is about 190°C — a little hotter, good for pies and some breads
• 400°F is about 200°C — roasting vegetables, crisping things up
• 425°F is about 220°C — high heat for a good roast or pizza-adjacent bakes
• 450°F is about 230°C — hot and fast, like for some artisan loaves

The gas mark system, decoded

If you've ever stared at a recipe asking for "gas mark 4" and felt completely lost, you're not alone. Gas mark is an older British system numbered from 1 (coolest) on up, and each step is roughly 25°F, or about 14°C, apart. Here are the ones I see most:

• Gas mark 2 ≈ 300°F ≈ 150°C
• Gas mark 4 ≈ 350°F ≈ 180°C (this is the most common "moderate oven")
• Gas mark 6 ≈ 400°F ≈ 200°C
• Gas mark 7 ≈ 425°F ≈ 220°C
• Gas mark 9 ≈ 475°F ≈ 240°C

So when a beloved old British recipe says gas mark 4, you can confidently set your oven to 350°F and carry on.

Fan and convection ovens run hotter than the number

This is the one that catches people, including me when I first used a convection oven. A fan (convection) oven circulates hot air, so it cooks more efficiently and effectively runs hotter than a conventional oven set to the same temperature. The standard fix is to drop the temperature by about 20°C, or roughly 25°F, when a recipe was written for a conventional oven and you're using fan/convection.

So a recipe that says 350°F conventional becomes about 325°F on convection. Some recipes, especially European ones, already give you a separate "fan" temperature. If yours does, use that number directly instead of subtracting again.

Why does my oven seem to bake hotter or cooler than the dial says?

Because most ovens are a little bit off, and some are wildly off. The dial is a target, not a promise. I learned this the hard way when things kept browning faster than the recipe claimed. The fix is cheap: an oven thermometer. You set one on the rack, preheat, and see what your oven is actually doing versus what the dial says. Mine runs a touch hot, so I adjust for it without thinking now. If your bakes are always overdone or underdone no matter how careful you are, an off oven is very often the culprit.

A few habits that keep my baking on track

• Always preheat fully. Give the oven time to actually reach temperature, not just the moment the light clicks off.
• Know your oven's hot spots. Rotate pans partway through if one side browns faster.
• Convert once, write it down. If you bake a recipe often, jot the converted temperature right on the page so you're not redoing the math every time.

If you want something to actually put in that perfectly-tuned oven, I share what I bake over on my recipes page. And if conversions are your thing, take a look at my other free tools for the kitchen.