Fahrenheit to Celsius (°F to °C)
1 degree Fahrenheit equals -17.22222222 degrees Celsius.
How to convert degrees Fahrenheit to degrees Celsius
Converting degrees Fahrenheit to degrees Celsius is not a simple multiplication, so use the formula below.
°C = (°F − 32) × 5/9
Example: 10 degrees Fahrenheit = -12.22222222 degrees Celsius.
Temperature scales have different zero points, so converting is not just multiplication. Differences in degrees convert differently from absolute readings.
About these units
Degree Fahrenheit (°F)
The temperature scale used in the United States and a few other countries: water freezes at 32 °F and boils at 212 °F. Proposed by Daniel Gabriel Fahrenheit in 1724.
Daniel Gabriel Fahrenheit, who lived from 1686 to 1736, proposed his scale in 1724. His zero came from a freezing mixture of ice, water and ammonium chloride (or sea salt), which holds a stable temperature, and his upper reference of about 96 was his estimate of human body temperature. His own letters say he built on Ole Rømer's scale. Accounts of how he picked zero differ, and a popular German story that it was the coldest winter day in his home city of Danzig has failed verification.
Around 1776 to 1777 a Royal Society committee led by Henry Cavendish fixed water's freezing point at 32 degrees and its boiling point at 212, exactly 180 degrees apart, which moved body temperature to about 98.6. Today the scale is defined through the kelvin; NIST puts absolute zero at minus 459.67 degrees Fahrenheit. It remains in everyday use in the United States and its territories, Palau, the Federated States of Micronesia, the Marshall Islands and the Cayman Islands. A comfortable room is around 70 degrees, which is about 21 degrees Celsius.
0 degrees Fahrenheit = 255.3722222 kelvins (approximately).
Sources: Wikipedia: Fahrenheit; NIST: the kelvin and the SI redefinition; NIST Guide to the SI, Appendix B.8: conversion factors
Degree Celsius (°C)
The metric temperature scale used worldwide for weather and daily life: water freezes at 0 °C and boils at 100 °C at standard pressure. Named after Anders Celsius.
Anders Celsius, a Swedish astronomer, proposed a scale in 1742 that ran the opposite way from the one we use: 0 for the boiling point of water and 100 for its freezing point. Credit for flipping it is shared and partly disputed. French physicist Jean-Pierre Christin published a reversed mercury thermometer in 1743, Carl Linnaeus is usually credited with reversing it in 1744, the year Celsius died, and others in Sweden, including Pehr Elvius, Daniel Ekström and Mårten Strömer, are also named as independent developers.
For much of the nineteenth century the scale was called centigrade, until the CGPM and CIPM adopted the name degree Celsius in 1948, partly to honor Celsius and to avoid confusion with a French term for a subdivision of the gradian. From 1954 to 2019 it was defined through absolute zero and the triple point of water; since 2019 it is tied to the Boltzmann constant. Strictly, water boils at about 99.974 degrees on the modern international temperature scale, not exactly 100. Australian weather reports switched exclusively to Celsius in 1972.
0 degrees Celsius = 273.15 kelvins (exactly).
Sources: Wikipedia: Celsius; BIPM: 9th CGPM (1948), Resolution 7; NIST: the kelvin and the SI redefinition
Related conversions
- Celsius to Fahrenheit (reverse)
- Fahrenheit to kelvin
- Fahrenheit to Rankine
- Fahrenheit to Réaumur
- Fahrenheit to Delisle
- Fahrenheit to Newton
- Fahrenheit to Rømer
- Kelvin to Celsius
- Rankine to Celsius
- Réaumur to Celsius
- Delisle to Celsius
- Newton to Celsius
- Rømer to Celsius
See all temperature units.