Degree Celsius (°C)
Definition
The Celsius scale, defined through the kelvin as t/°C = T/K − 273.15; it was originally calibrated so that water froze at 0 °C and boiled at about 100 °C at 1 atm.
History
The Celsius scale was proposed by the Swedish astronomer Anders Celsius in 1742, originally with 0 for boiling and 100 for freezing; the scale was soon reversed to the familiar form. It is now defined through the kelvin, with a temperature in degrees Celsius equal to the same temperature in kelvin minus 273.15.
Where it is used
Celsius is the everyday temperature scale almost everywhere for weather, cooking and body temperature; the United States is the main exception, using Fahrenheit.
Typical uses include weather outside the US, cooking, body temperature.
Conversion pages
These pages convert degree Celsius to or from another unit in temperature.
Other Temperature units
Sources
- BIPM SI BIPM, The International System of Units (SI), 9th ed. (2019) · Dataset reviewed Nov 11, 2026