Quick example
Convert a 350 °F recipe for a Celsius oven
The exact conversion of 350 °F is about 176.7 °C. Recipes and oven controls normally round that to 180 °C. A common fan-oven setting is 160 °C fan, and the nearest traditional setting is gas mark 4.
Oven conversion chart
Common Fahrenheit, Celsius, fan, and gas-mark settings
| Gas mark | Conventional °C | Conventional °F | Fan °C | Description |
|---|---|---|---|---|
| ¼ | 110 °C | 225 °F | 90 °C | Very cool |
| ½ | 120 °C | 250 °F | 100 °C | Very cool |
| 1 | 140 °C | 275 °F | 120 °C | Cool |
| 2 | 150 °C | 300 °F | 130 °C | Cool |
| 3 | 160 °C | 325 °F | 140 °C | Moderate |
| 4 | 180 °C | 350 °F | 160 °C | Moderate |
| 5 | 190 °C | 375 °F | 170 °C | Moderately hot |
| 6 | 200 °C | 400 °F | 180 °C | Moderately hot |
| 7 | 220 °C | 425 °F | 200 °C | Hot |
| 8 | 230 °C | 450 °F | 210 °C | Hot |
| 9 | 240 °C | 475 °F | 220 °C | Very hot |
| 10 | 260 °C | 500 °F | 240 °C | Very hot |
Exact math, usable dial
Why oven equivalents are rounded
Celsius and Fahrenheit have an exact mathematical relationship: subtract 32 from Fahrenheit and multiply by 5/9, or multiply Celsius by 9/5 and add 32. Real recipes usually round the answer to 10-degree Celsius or 25-degree Fahrenheit increments because those are common oven settings.
Conventional oven
Uses the top and bottom heating elements without continuous fan circulation.
Fan oven
This tool starts 20 °C below the conventional Celsius setting. Oven and recipe guidance can differ.
Gas mark
A discrete scale rather than a formula. The converter chooses the nearest traditional table entry.
Oven variation
Thermostat accuracy, rack position, cookware, and door opening can all affect actual heat.
Check the appliance
Fan conversion is a starting point
Fan-assisted ovens move hot air around the food, but models and cooking modes vary. Use the converted temperature as a practical starting point, then prefer the recipe and appliance instructions and check food for doneness at the appropriate time.
Some ovens have automatic convection conversion. Check your manual before entering an already reduced setting, so the appliance does not apply another reduction. This tool does not adjust cooking times.
Convert once
How to convert 425 °F to a fan-oven setting
First change the scale: (425 − 32) × 5/9 ≈ 218.3 °C conventional. Then apply this tool's fan guidance: 218.3 − 20 ≈ 198.3 °C, rounded to 200 °C fan.
The ordinary Celsius–Fahrenheit formula changes the temperature scale; the fan adjustment changes the suggested cooking setting. They are different steps. For scale conversion without oven guidance, use the temperature converter.
If the recipe already says 160 °C fan, choose the fan input option above. Under the same convention, that corresponds to 180 °C conventional; it should not be reduced to 140 °C fan.
Method & sources
How the conversion guidance is built
Exact Celsius and Fahrenheit math follows the NIST temperature conversion equations. Rounded descriptions follow NIST's approximate oven ranges, while the discrete gas settings are based on published conversion tables from the North London Waste Authority and Oldham Council.
The 20 °C fan reduction is a convention, not a universal appliance rule. For example, Whirlpool's convection guidance discusses a 25 °F reduction and automatic-conversion features on some models. A 25 °F reduction is about 14 °C, not 20 °C; follow your own oven manual when its instructions differ.
Common questions
Oven temperature conversion FAQ
What is 350 °F in Celsius for an oven?
350 °F converts to approximately 176.7 °C. The suggested rounded setting is 180 °C conventional or 160 °C fan under this calculator's 20 °C adjustment.
What is 425 °F in Celsius for a fan oven?
425 °F is approximately 218.3 °C conventional. This calculator suggests 220 °C conventional, 200 °C fan, or gas mark 7. The fan setting is guidance, not an exact temperature-scale equivalence.
What if the recipe already gives a fan temperature?
Select Fan oven — Celsius and enter that temperature. Do not treat it as conventional Celsius and subtract the fan adjustment a second time. For example, 160 °C fan corresponds to 180 °C conventional under this tool's convention.
Is a 20 °C reduction the same as a 25 °F reduction?
No. A temperature reduction of 20 °C equals a reduction of 36 °F. Some convection-oven instructions use a 25 °F reduction instead. Follow your own appliance instructions when they differ from the 20 °C convention used here.
What temperature is gas mark 4?
Gas mark 4 is commonly listed as 180 °C conventional or 350 °F, with 160 °C fan as a general starting point.
Does this converter change the cooking time?
No. It suggests temperature settings only. Cooking time depends on the recipe, food, pan, and appliance; a temperature conversion alone cannot determine it.