Why recipes round oven temperatures
The exact conversion of 350 °F is 176.7 °C, but you will hardly ever see that in a recipe. Recipes and oven dials work in steps: 10 °C in Celsius, 25 °F in Fahrenheit and whole marks on a gas oven. So 350 °F becomes 180 °C, and 200 °C becomes 400 °F, even though the exact figure is 392 °F.
That rounding does not hurt your baking. A few degrees are well inside how much a home oven drifts while it heats and cycles. The converter shows both numbers: the exact conversion, and the rounded oven setting you would actually turn the dial to.
Gas mark charts are older than metric recipes, and their Celsius column was rounded by hand. That is why gas mark 3 shows up as 160 °C in some charts and 170 °C in others, while the exact conversion of 325 °F is 162.8 °C.
Fan oven vs conventional baking
A conventional oven heats with elements at the top and bottom, and the air inside moves only by itself. A fan oven, called a convection oven in the US, blows the hot air around the food. Moving air carries heat more quickly, so food browns and cooks faster at the same temperature.
- Fan oven: set it about 20 °C lower than the conventional temperature in the recipe.
- US convection: set it about 25 °F lower, or keep the temperature and check the food earlier.
- Check the manual: some ovens lower the temperature automatically in convection mode, so lowering it yourself would make it too low.
Delicate bakes such as soufflés, custards and some cakes can rise unevenly in a strong fan. For those, many bakers switch to conventional heat if the oven offers it.
Check your oven with a thermometer
The number on the dial is what the oven aims for, not always what it reaches. Hang an oven thermometer in the middle of the oven, heat it to 180 °C or 350 °F, wait 20 minutes and read it. If it shows a different number, set the dial higher or lower by the difference from then on. Doing this once explains many cakes that sink or cookies that burn before the time is up.
How to use the oven temperature converter
- 1Type the temperature from your recipe and choose °F, °C or gas mark. Gas marks can be typed as 1/4, 1/2 or a whole number.
- 2Read the rounded oven setting and the exact conversion, plus the gas mark.
- 3Baking in a fan or convection oven? Use the fan setting instead. Tap any row in the chart to convert it.
Frequently asked questions
What is 350 °F in Celsius?
Exactly 176.7 °C. Recipes and oven dials round it to 180 °C, which is also gas mark 4. In a fan oven, set about 160 °C instead.
How much lower should I set a fan oven?
A common rule is about 20 °C lower than the conventional temperature in the recipe, or about 25 °F lower for a US convection oven. Some ovens make this adjustment for you, so check the manual before you lower it twice.
Is the temperature in my recipe for a fan or a conventional oven?
Most recipes give the conventional temperature unless they say fan, convection or fan-forced. Many British and Australian recipes list both, often written like 180 °C (160 °C fan). If a recipe gives only one number and no hint, assume conventional.
What gas mark is 200 °C?
Gas mark 6, which is 400 °F. Each gas mark from 1 to 9 is 25 °F apart, starting at 275 °F for gas mark 1, and the half and quarter marks go down to 250 °F and 225 °F.
Why does my cake bake faster or slower than the recipe says?
Home ovens are often off by quite a bit, run hotter in some spots than others and swing up and down while the heating element cycles. An inexpensive oven thermometer shows what your oven really reaches, so you can adjust the dial instead of the baking time.