Temperature Converter
Convert temperatures between Celsius, Fahrenheit, Kelvin, and Rankine — with a reference chart of common temperatures.
Temperature conversion is one of the most searched unit conversions, driven by international travel, cooking, weather, and science. The formula for Celsius to Fahrenheit (multiply by 9/5 then add 32) is one of those things people look up repeatedly rather than memorizing. Having it instant removes that friction.
The only temperature where Fahrenheit and Celsius agree: -40°. At that point, -40°F = -40°C. Below that, Fahrenheit numbers are higher than Celsius. Above that, Celsius numbers are lower than Fahrenheit for the same temperature.
The four temperature scales
Fahrenheit: US customary scale. Water freezes at 32°F, boils at 212°F. Developed by Daniel Gabriel Fahrenheit in 1724. Celsius: International metric scale (formerly centigrade). Water freezes at 0°C, boils at 100°C. Used by virtually all countries outside the US. Kelvin: Absolute temperature scale used in science. 0 K is absolute zero (no molecular motion). Water freezes at 273.15 K, boils at 373.15 K. No negative values possible. Rankine: Absolute scale using Fahrenheit-sized degrees. Used in some US engineering contexts.
Frequently asked questions
What is a normal body temperature in Celsius?
37.0°C (98.6°F) is the traditional average, though research suggests the average may be closer to 36.6°C (97.9°F). Fever is generally defined as above 38°C (100.4°F). Normal range is approximately 36.1-37.2°C (97-99°F).
What temperature is absolute zero?
-273.15°C (-459.67°F) or 0 K. It is the theoretical minimum temperature, where atoms would have no kinetic energy. It has never been reached but has been approached to within billionths of a degree in laboratory conditions.