About the Oven Temp Converter
Oven temperature shows up in three different scales depending on where a recipe comes from - Fahrenheit in the US, Celsius almost everywhere else, and Gas Mark in older UK recipes and some British ovens. Getting the conversion wrong by even one gas mark can meaningfully change how a bake turns out.
How It Works
The calculator converts your Fahrenheit or Celsius input to the other scale using the standard linear conversion formula, then finds the closest UK Gas Mark from the standard reference table used by British recipes and oven manufacturers.
Formula & Methodology
Fahrenheit and Celsius convert exactly using a fixed linear formula, so there's no approximation involved for that half of the conversion. Gas Mark, however, is a stepped scale with only 11 defined points (¼ through 9), not a continuous one - so converting to Gas Mark means finding whichever of those 11 reference points is closest to your Celsius value, the same way UK recipes and gas oven dials are calibrated.
Step-by-Step: Calculating It By Hand
- 1If starting from Fahrenheit, subtract 32, then multiply by 5/9 to get Celsius.
- 2If starting from Celsius, multiply by 9/5, then add 32 to get Fahrenheit.
- 3Compare your Celsius value against the standard Gas Mark reference table (Gas Mark 4 = 180°C, Gas Mark 6 = 200°C, and so on).
- 4Pick whichever Gas Mark value is numerically closest to your Celsius temperature.
Examples
A US recipe in a UK oven
A recipe calling for 350°F converts to 177°C, which rounds to Gas Mark 4 (180°C) - close enough that most bakers would set the dial to 4.
A UK recipe in a US oven
Gas Mark 6 corresponds to 200°C, which converts to 392°F - most US ovens would be set to 400°F, the nearest common increment.
Advantages
- Converts all three scales at once instead of one pair at a time
- Shows the full Gas Mark reference table for context, not just your one result
- Uses the exact linear formula for F/C, not a rounded rule of thumb
Common Mistakes
- Treating Gas Mark as a precise, continuous scale instead of a stepped one
- Forgetting that fan (convection) ovens typically run hotter than the same dial setting on a conventional oven
- Using "divide by 2, add 30" mental math shortcuts instead of the exact formula for anything precision-sensitive like baking
Common Use Cases
- Following a British recipe on a US or Celsius-only oven
- Following a US recipe on a UK gas oven
- Double-checking an oven's dial markings against a recipe from an unfamiliar region