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Oven Temperature Conversion: °F, °C and Gas Mark
350°F is 177°C by the math, 180°C on a recipe, and gas mark 4 on a UK oven. All three are correct. This page lays out why, and which one to set.
No. 12 — Volume & Liquid
Kitchen Conversions
Set an amount, pick what you have and what you need. Works both directions, gallons down to milliliters.
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Fahrenheit, Celsius and gas mark chart
Gas mark is the numbered dial found on many British and Irish gas ovens. The Celsius column is the rounded value recipes normally print, which is what you set on a Celsius oven.
| Gas mark | °F | °C | Description |
|---|---|---|---|
| ¼ | 225 | 110 | Very slow |
| ½ | 250 | 130 | Very slow |
| 1 | 275 | 140 | Slow |
| 2 | 300 | 150 | Slow |
| 3 | 325 | 170 | Moderately slow |
| 4 | 350 | 180 | Moderate |
| 5 | 375 | 190 | Moderately hot |
| 6 | 400 | 200 | Moderately hot |
| 7 | 425 | 220 | Hot |
| 8 | 450 | 230 | Hot |
| 9 | 475 | 240 | Very hot |
Exact conversion versus what recipes print
The formula is °C = (°F − 32) × 5/9. Applied to common oven settings it gives awkward numbers, so recipe writers round to the nearest setting a Celsius dial offers.
| °F | Exact °C | Typical recipe °C |
|---|---|---|
| 300 | 149 | 150 |
| 325 | 163 | 160 or 165 |
| 350 | 177 | 180 |
| 375 | 191 | 190 |
| 400 | 204 | 200 |
| 425 | 218 | 220 |
| 450 | 232 | 230 |
| 475 | 246 | 240 or 250 |
| 500 | 260 | 260 |
The differences are 3°C or less in almost every row. No home oven holds a temperature that tightly, so the rounded number is the right one to use.
A mental shortcut
For a quick estimate with no calculator: subtract 32, halve the result, then add a tenth of the halved number. For 350°F, subtract 32 to get 318, halve it to get 159, and add 16 to land on about 175°C. It's within 2 degrees of the exact answer and works for every oven temperature.
Fan ovens and convection
A fan (convection) oven circulates hot air, so food cooks faster than at the same temperature in a conventional oven. The usual rule is to lower the temperature by about 20°C, or 25°F, from what the recipe says. A recipe that calls for 180°C in a conventional oven becomes 160°C in a fan oven.
Some ovens do this adjustment for you in a "convection bake" mode, and some leave it manual. Check your manual. If you're unsure, set the temperature as written and look at the food ten minutes early.
Why your oven isn't the temperature on the dial
Home ovens are often off by 15°F or more, and they swing above and below the setpoint as the heating element cycles. A cheap oven thermometer hung from a rack shows you what's actually happening. If yours runs 25 degrees hot, you can set it 25 degrees lower and stop burning the bottoms of cookies. See the oven thermometer on our tools page.
Frequently asked questions
What is 350°F in Celsius?
177°C exactly. Recipes round it to 180°C, and on a gas oven it's gas mark 4.
What is 400°F in Celsius?
204°C exactly, usually printed as 200°C. That's gas mark 6.
What is 180°C in Fahrenheit?
356°F exactly. Set an American oven to 350°F.
What gas mark is 375°F?
Gas mark 5, which is 190°C.
Do I lower the temperature for a glass dish?
Many bakers lower it by 25°F when using glass or dark-coated metal pans, because both absorb heat faster than shiny aluminum and can brown the edges before the center sets. Follow the recipe if it names the pan material.