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Guide · 7 min read · 27 Jul 2026

Celsius to Fahrenheit for oven temperatures

The formulas, the gas marks, and the fan-oven adjustment charts forget.

Few kitchen tasks cause more quiet panic than opening a recipe and finding the oven temperature in a scale you do not use. If you cook in Fahrenheit and the recipe says 180°C, or you cook in Celsius and it says 350°F, you need a fast, reliable way to convert — and ideally to understand it, so you are not hunting for a chart every time. This guide covers the exact formulas, the handful of temperatures worth memorising, gas marks, and the fan-oven adjustment that most charts forget to mention.

Getting oven temperature right is not a minor detail. An oven even 20 degrees off from what a recipe intends can mean the difference between a cake that rises evenly and one that sinks, between chicken skin that crisps and skin that steams, between a loaf with a good crust and one that stays pale. Because baking in particular relies on precise heat to trigger the chemical reactions that set structure and colour, a confident conversion is one of the most useful skills in the kitchen — and it takes only the two formulas below to master.

The two formulas

Everything rests on two conversions:

  • Celsius to Fahrenheit: multiply by 9/5 (that is 1.8) and add 32. So °F = (°C × 1.8) + 32.
  • Fahrenheit to Celsius: subtract 32, then multiply by 5/9. So °C = (°F − 32) × 5/9.

Worked example: to convert 180°C, multiply by 1.8 to get 324, then add 32 to get 356°F. Going the other way, 350°F minus 32 is 318, times 5/9 is about 177°C. Notice that 350°F and 180°C are close but not identical — 350°F is really 176.7°C. In practice recipes round to convenient oven settings, which is why you will see 350°F treated as both 175°C and 180°C depending on the source.

The temperatures worth memorising

You do not need to convert from scratch every time. These are the common baking and roasting temperatures, rounded the way real recipes round them:

  • 275°F = 140°C — very low, slow roasting and meringues
  • 300°F = 150°C — low, slow cooking
  • 325°F = 160°C — low-moderate
  • 350°F = 180°C — the default baking temperature for cakes and cookies
  • 375°F = 190°C — moderate-hot
  • 400°F = 200°C — hot, for roasting vegetables and some breads
  • 425°F = 220°C — very hot, roasting and pizza
  • 450°F = 230°C — very hot; note this is 230°C, not 232°C rounded up oddly
  • 475°F = 245°C — extremely hot

One conversion mistake shows up often enough to warn about: 450°F converts to about 232°C, which some charts wrongly print as a much higher number. If a conversion ever looks dramatically off from the pattern above, treat it with suspicion and recompute with the formula. A dedicated oven temperature converter avoids these transcription errors entirely.

Gas marks, decoded

Older UK and Irish ovens use gas marks instead of degrees. The scale is simpler than it looks: gas mark 1 is 275°F (about 135–140°C), and each step up adds 25°F. So gas mark 4 — the everyday baking setting — is 350°F or 180°C, the same default temperature that dominates recipes worldwide. Here are the common ones:

  • Gas mark 1 = 275°F = 140°C
  • Gas mark 2 = 300°F = 150°C
  • Gas mark 3 = 325°F = 170°C
  • Gas mark 4 = 350°F = 180°C
  • Gas mark 5 = 375°F = 190°C
  • Gas mark 6 = 400°F = 200°C
  • Gas mark 7 = 425°F = 220°C
  • Gas mark 8 = 450°F = 230°C
  • Gas mark 9 = 475°F = 240°C

The fan-oven adjustment nobody mentions

Here is the step that ruins bakes even when the conversion is perfect. Fan ovens (also called convection or fan-assisted) circulate hot air, so they cook faster and more evenly than conventional ovens at the same dial setting. The standard correction is to lower a fan oven by about 20°C (roughly 25°F) compared with the conventional temperature, or shorten the cooking time. So a recipe written for 180°C conventional becomes about 160°C in a fan oven. If your bakes brown too fast on the outside while staying underdone inside, an un-adjusted fan oven is the usual culprit.

Why the two scales exist at all

Fahrenheit, still standard in the United States, sets water's freezing point at 32° and boiling at 212°, a 180-degree span. Celsius, used almost everywhere else and throughout science, sets freezing at 0° and boiling at 100°. Neither is "more correct" — they are just different reference choices. The 180-degree versus 100-degree spread is exactly why the conversion factor is 180/100, which simplifies to 9/5. Understanding that makes the formula feel less arbitrary: you are rescaling one span onto the other and shifting the zero point.

Practical tips for accurate results

Ovens lie. Most home ovens are off by 10–15 degrees from their dial, and many have hot spots. If your results are consistently under- or over-done despite correct conversions, an inexpensive oven thermometer will tell you the truth and let you compensate. Rounding to the nearest available setting (few ovens offer 356°F, so you use 350°F) is normal and rarely matters. Where precision genuinely counts — sugar work, delicate custards, laminated pastry — convert exactly with a temperature converter and trust a thermometer over the dial.

Quick answers to common questions

What is 350°F in Celsius? About 177°C, usually rounded to 175°C or 180°C on the dial.

What is 180°C in Fahrenheit? 356°F, which recipes round to 350°F.

What is gas mark 4? 350°F or 180°C — the everyday baking temperature.

Do I lower the temperature for a fan oven? Yes, by about 20°C (roughly 25°F) compared with a conventional oven, or shorten the time.

The bottom line

Memorise 350°F = 180°C = gas mark 4 as your anchor, remember that each gas mark is 25°F, and drop a fan oven by about 20°C. With those three facts and the two formulas, you can cook confidently from any recipe in the world. For everything in between, a converter turns a moment of doubt into a two-second lookup.

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