Why are there so many different scales?
Recipes from different countries use different temperature scales: recipes from Brazil and most of the world use Celsius, American recipes use Fahrenheit, and older British recipes often use Gas Mark (a numbered scale from 1 to 9 used on gas ovens in the UK). When following a foreign recipe, it's easy to get the oven temperature wrong if you don't convert correctly — an error of 20-30°C (35-55°F) can ruin a cake or bread.
Conversion formulas
Fahrenheit = Celsius × 9/5 + 32 and Celsius = (Fahrenheit − 32) × 5/9. The Gas Mark scale doesn't follow a simple mathematical formula — it's a fixed correspondence table defined by British stove manufacturers, which this calculator uses to find the closest Gas Mark to the entered temperature.
Frequently asked questions
What does "moderate oven" mean in an old recipe?
It's a qualitative description common in older recipes (before ovens with precise thermostats became widespread), usually corresponding to somewhere around 350-375°F (180-190°C) — this calculator shows the matching description for any temperature, making it easier to read recipes that use these terms.
Why might my oven not match the marked temperature exactly?
Home ovens, especially older ones or those without a calibrated thermostat, can have a real variance of up to 20-25°F (10-15°C) from the temperature set on the dial — an independent oven thermometer is the most reliable way to confirm the actual temperature, especially for baking recipes that require precision.