The centigrade scale is essentially identical to the Celsius scale, the standard scale by which temperature is measured in most of the world. Anders Celsius of Sweden first devised the centigrade scale in the early 18th century. But in his version, 100° marked the freezing point of water, and 0° its boiling point. Later users found it less confusing to reverse these two. To convert Fahrenheit degrees to centigrade, subtract 32 and multiply by 5/9. To convert centigrade to Fahrenheit, multiply by 9/5 and add 32.