Temperature Converter

Reviewed by the CalculatorHub team, edited by James Graham. NIST-defined conversions. Last verified 13 June 2026.

Temperature is measured on three scales in common use today: Celsius, Fahrenheit, and Kelvin. Celsius, also called centigrade, sets 0 degrees as the freezing point of water and 100 degrees as its boiling point at standard atmospheric pressure, and is the standard unit of temperature in most of the world for everyday use and in scientific contexts. Fahrenheit, primarily used in the United States for everyday weather and cooking, sets 32 degrees as the freezing point of water and 212 degrees as the boiling point, with normal human body temperature around 98.6 degrees. Kelvin is the base unit of thermodynamic temperature in the International System of Units (SI), as defined by the National Institute of Standards and Technology (NIST). Kelvin uses the same scale increment as Celsius but starts at absolute zero, the theoretical lowest possible temperature, which equals minus 273.15 degrees Celsius. To convert Celsius to Fahrenheit, multiply by 9/5 and add 32. To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9. To convert Celsius to Kelvin, add 273.15. This calculator shows all three temperatures simultaneously: type in any one of the three fields and the other two update instantly. A reference table of common temperatures (absolute zero, water freezing and boiling, typical body temperature, standard oven settings) is included below for quick reference.