Temperature converters

About temperature conversions

Celsius, Fahrenheit, and Kelvin all measure the same physical quantity — how hot or cold something is — but they disagree on where zero sits and how big one degree is, which means you cannot convert between them with a simple multiplier the way you can with length or weight. Oven dials, weather forecasts, lab equipment, and imported appliance manuals frequently mix scales, and a recipe written for a 180°C oven will not turn out right if you read "180" on a Fahrenheit dial instead — that is a difference of over 150 actual degrees.

Celsius sets water's freezing point at 0° and boiling point at 100° at standard atmospheric pressure, which is why it is the default for cooking, weather, and daily life across most of the world. Fahrenheit, used mainly in the United States, sets freezing at 32° and boiling at 212°, giving finer granularity for describing outdoor comfort (a "70-degree day" feels meaningfully different from a "75-degree day," a distinction Celsius collapses into two or three degrees). Kelvin starts at absolute zero — the theoretical point where molecular motion stops — and is the scale physics and chemistry use because it has no negative numbers and aligns directly with thermodynamic laws.

Our temperature converters use the standard affine formulas rather than rough mental shortcuts: °F = (°C × 9/5) + 32, °C = (°F − 32) × 5/9, and K = °C + 273.15. A common shortcut — "double the Celsius figure and add 30" — is close enough for casual weather chat but drifts several degrees off at oven and freezer temperatures, exactly where the error matters most for food safety and baking results.

Beyond the oven, temperature conversion errors show up in less obvious places: importing a European car with a coolant temperature gauge calibrated in Celsius, reading a US medical thermometer against a European fever threshold quoted in Celsius, or interpreting a scientific paper that reports results in Kelvin. Anchor a few reference points in memory — water freezes at 0°C/32°F, body temperature is about 37°C/98.6°F, water boils at 100°C/212°F — and use these converters whenever you need an exact figure rather than a rough feel.

Read our full Celsius and Fahrenheit guide for a deeper set of reference points, common baking temperature equivalents, and the reasoning behind each scale's history, or jump straight to the specific converter you need below.

Related reading: Celsius and Fahrenheit explained