Oven temperature converter

Convert between Celsius, Fahrenheit, gas mark and fan-oven settings, showing the arithmetic at each step.

What it answers

What is this oven temperature in the scale my oven uses?

What it assumes

  • The Celsius-to-Fahrenheit conversion is exact arithmetic.
  • The fan adjustment applies the widely used convention of reducing the set temperature by 20 °C, which is a rule of thumb rather than a physical constant.
  • Gas marks are a coarse scale, so a converted value is matched to the nearest mark and the exact equivalent is shown alongside it.

What have you got?

The scale your recipe uses

Equivalents

Exact conversions

Celsius, conventional oven
180 °C
Fahrenheit
356 °F

Conventions, not exact

Fan oven setting
160 °C
Nearest gas mark
4

The fan figure applies the widely used 20 °C reduction, which varies by oven. The gas mark is the nearest on a coarse scale — it represents exactly 180 °C.

How this was calculated

  1. Celsius to Fahrenheit

    Formula
    F = C × 9 ÷ 5 + 32
    With your numbers
    F = 180 × 9 ÷ 5 + 32
    Result
    F = 356 °F — exact arithmetic
  2. Conventional to fan setting

    Formula
    C(fan) = C − 20
    With your numbers
    C(fan) = 180 − 20
    Result
    C(fan) = 160 °C — a widely used convention, and it varies by oven
  3. Nearest gas mark

    Formula
    Matched to the closest entry in the gas-mark table
    With your numbers
    Closest to 180 °C
    Result
    Gas mark 4, which is exactly 180 °C

A converted number is only as good as the oven applying it. Domestic ovens frequently run some way from their dial setting, and the discrepancy causes faults that look exactly like recipe problems — see fan ovens and the note on verifying an oven temperature in diagnosing a bake that went wrong.

What it cannot tell you

IT DOES NOT CONVERT TO AN AIR FRYER, and no reliable general conversion exists. An air fryer is a small fan oven with a powerful fan and very little thermal mass, so it heats fast, browns hard and varies enormously between models. Published conversions — typically 20 °C down and a shorter time — are the fan-oven adjustment applied twice, which is a starting guess rather than arithmetic. Check early and often.

IT CONVERTS TEMPERATURE AND NOT BAKING TIME. A lower number on a fan setting is not an instruction to bake for the same duration — moving air transfers heat faster, so the time usually shortens as well, and by how much depends on the product rather than on the arithmetic. Check early.

Domestic ovens frequently run some way from their dial setting. A converted number is only as good as the oven applying it, and an oven thermometer is worth more than any conversion.

The 20 °C fan reduction varies by oven and by product, and works less well for delicate items where moving air can set a surface early.

Gas mark equivalents differ slightly between published tables. BakeHQ shows the exact conversion as well as the nearest mark so the approximation is visible rather than hidden.

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