Why is the formula degrees fahrenheit equals 1.8 times degrees celsius plus 32?
On the Celsius scale, the freezing and boiling points of water are 100 degrees apart, hence the unit of this scale. A temperature interval of one degree Fahrenheit is an interval of 5⁄9 of a degree Celsius. The Fahrenheit and Celsius scales coincide at −40 degrees (i.e. −40 °F and −40 °C describe the same temperature).
