Both Celsius and Fahrenheit are temperature measurement systems developed by scientists in the 1700′s. The Celsius system was credited to Anders Celsius, a Swedish astronomer, who invented a virtually identical system 2 years before his death. Celsius’ original measurements where simply reversed; 100 degrees Celsius, in his original system was the freezing point of water and 0 degrees was the boiling point. The term Centigrade was used interchangeably with Celsius: “Centi” meaning 100 and “grade” meaning steps and seemed to be a more apt description for this measurement system, but was officially changed to Celsius in 1948 to avoid confusion, as the term Centigrade is used by the Spanish and French as a unit of angular measurement.

The Fahrenheit scale was developed by Daniel Gabriel Fahrenheit, a German physicist who based his scale on the work of Romer. Fahrenheit altered Romer’s scale by multiplying each standard Romer gradation (boiling and freezing) by 4. This allowed for larger numbers to be used, eliminating the need for fractional measurements.

The Celsius scale is by far the most widely used measure of temperature with a few exceptions; the United States and Belize still commonly use the Fahrenheit scale, although the worldwide scientific community, including in the US and Belize use the Celsius or Kelvin scale.

So; how do you convert Celsius to Fahrenheit and Fahrenheit to Celsius? Fahrenheit = (Celsius x 9/5) + 32 and Celsius = (Fahrenheit – 32) x 5/9

To make it easier to estimate; to convert Celsius to Fahrenheit, double and add 32 and to convert Fahrenheit to Celsius, subtract 32, then divide by 2. Thus; 100 degrees Fahrenheit is approximately 34 degrees Celsius. It is exactly 37.78 degrees Celsius. 15 degrees Celsius is approximately 62 degrees Fahrenheit. It is exactly 59 degrees Fahrenheit.