Oven Temperature Converter — °C, °F, and Gas Mark Conversions

The Formula

Oven temperature conversion involves three distinct scales: Celsius (used in most countries), Fahrenheit (used in the United States), and Gas Mark (a unique UK system that maps oven regulator settings to temperature ranges). Each Gas Mark increment represents approximately 14°C (25°F), with Gas Mark 4 (180°C / 350°F) serving as the standard moderate baking temperature. Fan or convection ovens typically require reducing the temperature by about 20°C (36°F) compared to conventional ovens, because the circulating air transfers heat more efficiently.

Variable Definitions

How to Use This Calculator

1. 1

   Enter the temperature value in the input field. For Gas Mark conversions, enter the Gas Mark number (e.g., 4 for Gas Mark 4, 0.25 for ¼, 0.5 for ½).

2. 2

   Select the unit you are converting from: °C, °F, or Gas Mark.

3. 3

   Select the unit you want to convert to: °C, °F, or Gas Mark.

4. 4

   Read the converted result instantly along with the equivalent temperature in all three scales and a descriptive oven term (e.g., "Moderate oven"). Use this for international recipes that specify unfamiliar temperature scales.

Quick Reference

Common Applications

• Baking international recipes that specify temperatures in unfamiliar units, such as converting a British Gas Mark recipe to Fahrenheit for a US oven
• Adjusting conventional oven recipes for fan or convection ovens by reducing the temperature by 20°C (36°F)
• Understanding vintage cookbooks that use Gas Mark settings before modern digital temperature controls
• Converting oven temperatures for foods like bread, pastries, and roasted meats where precise temperature control is critical for proper texture and doneness
• Translating recipe temperatures for kitchen appliances with different display scales, such as using an air fryer or toaster oven that defaults to Celsius

Oven temperature scales compared side by side with descriptive oven terms. Fan ovens typically require a 20°C reduction.

Understanding the Concept

Oven temperature conversion is an essential skill for any cook or baker working with international recipes. Unlike simple unit conversions, oven temperature scales include the unique Gas Mark system, a method developed for traditional British gas ovens where the thermostat dial was marked with numbers rather than specific temperatures. The Gas Mark system works on an approximately linear scale: Gas Mark 1 corresponds to 140°C (275°F), and each subsequent mark increases by roughly 14°C (25°F) up to Gas Mark 10 at 260°C (500°F). This means Gas Mark 4 (180°C / 350°F) is the standard moderate oven temperature used for most baking. A critical consideration in oven temperature conversion is whether you are using a conventional oven or a fan-assisted (convection) oven. Fan ovens circulate hot air using a built-in fan, which transfers heat more efficiently and evenly throughout the oven cavity. As a result, fan ovens reach the effective cooking temperature more quickly and maintain it more consistently. The general rule is to reduce the temperature by about 20°C (36°F) when converting a conventional oven recipe for use in a fan oven. For example, if a recipe calls for 180°C (350°F) in a conventional oven, set a fan oven to 160°C (320°F). If a recipe specifies fan oven temperature and you are using a conventional oven, increase by the same amount. Beyond the numbers, common oven terms like "moderate" or "hot" provide a rough guide: a moderate oven is 160–180°C (325–350°F), good for cakes and biscuits; a hot oven is 210–230°C (425–450°F), ideal for roasting vegetables and searing meats; and a very hot oven at 240–260°C (475–500°F) is used for pizzas and bread to achieve a crisp crust. Understanding these relationships allows you to confidently adapt any recipe regardless of the temperature scale or oven type specified.

Frequently Asked Questions

Sources & References