The degree Fahrenheit
The degree Fahrenheit (°F) is the customary temperature scale in the United States, defined since 1968 such that water freezes at exactly 32 °F and boils at exactly 212 °F at standard pressure — giving 180 Fahrenheit degrees over a range of 100 Celsius degrees. The scale was proposed in 1724 by Daniel Gabriel Fahrenheit, who calibrated zero against a brine ice bath. To convert °F to °C, subtract 32 then multiply by 5/9.