# How do the Fahrenheit and Celsius temperature scales compare?

Feb 3, 2014

The Fahrenheit scale is based on 32 °F for the freezing point of water and 212 °F for the boiling point of water, while the Celsius scale is based on -273.15 °C for absolute zero and 0.01 °C for the triple point of specially purified water.

The Fahrenheit scale is based on 32 °F for the freezing point and 212 °F for the boiling point of water. Thus, the boiling and freezing points of water are exactly 180 degrees apart.

The Celsius scale is based on exactly -273.15 °C for absolute zero and exactly 0.01 °C for the triple point of specially purified water, with 273.16 degrees between these two points. On the Celsius scale, the freezing point of water is still 0 °C, and the boiling point of water is still 100 °C (but these are not the definitions). Thus, the boiling and freezing points of water are 100 degrees apart. Therefore

180 F° = 100 C° or

1 F° = $\frac{5}{9}$

The formula to convert Celsius to Fahrenheit is F = $\frac{9}{5}$C + 32.

The formula to convert Fahrenheit to Celsius is C = $\frac{5}{9}$(F – 32).