Celsius to Fahrenheit: How to Convert and When It Matters

Temperature is one of the most common unit conversions people need — a recipe from an American cookbook, a weather forecast from a different country, or an oven setting that doesn't match your dial. Celsius and Fahrenheit measure the same thing but use completely different scales, which is why the numbers look so different.

The scales explained

Celsius sets 0° as the freezing point of water and 100° as the boiling point. It's the standard in most of the world and in all scientific contexts. Fahrenheit sets 32° as the freezing point and 212° as the boiling point of water — a scale defined before Celsius was standardised, and now primarily used in the United States.

The formula

To convert Celsius to Fahrenheit: multiply by 9, divide by 5, then add 32. In short: °F = (°C × 9/5) + 32.

To convert Fahrenheit to Celsius: subtract 32, multiply by 5, then divide by 9. In short: °C = (°F − 32) × 5/9.

Reference points worth knowing

• 0°C / 32°F — water freezes, very cold day.
• 20°C / 68°F — comfortable room temperature.
• 37°C / 98.6°F — normal human body temperature.
• 100°C / 212°F — water boils at sea level.
• 180°C / 356°F — common baking temperature.
• 200°C / 392°F — hot oven.

The rough shortcut

For a quick mental estimate: double the Celsius temperature and add 30. So 20°C is roughly 70°F (exactly 68°F). It's not precise, but it's close enough to know whether to bring a coat.

A converter handles the exact maths instantly — useful for cooking, travel, and any situation where you need the precise number rather than a rough estimate.