The Fahrenheit scale was replaced by the Celsius scale in most countries during the mid to late 20th century, though Canada retains it as a supplementary scale that can be used alongside Celsius.
Fahrenheit remains the official scale of the United States, Cayman Islands and Belize. The Rankine temperature scale was based upon the Fahrenheit temperature scale, with its zero representing absolute zero instead.
On the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit (°F) and the boiling point 212 °F (at standard atmospheric pressure). This puts the boiling and freezing points of water exactly 180 degrees apart.
Therefore, a degree on the Fahrenheit scale is 1⁄180 of the interval between the freezing point and the boiling point.
On the Celsius scale, the freezing and boiling points of water are 100 degrees apart.
A temperature interval of 1 °F is equal to an interval of 5⁄9 degrees Celsius.
The Fahrenheit and Celsius scales intersect at -40° (-40 °F and -40 °C represent the same temperature).
Did you know ?
Celcius used to be called Centigrade.