The degree Fahrenheit ( ^o F) is the unit of temperature used by most people in the United States in describing weather. The scale derives its name from a German-born physicist, Daniel Gabriel Fahrenheit, who is recognized as having invented it. At standard Earth-atmospheric sea-level pressure, pure water freezes at 32 ^o F and boils at +212 ^o F.

The size of the Fahrenheit "degree" is only 5/9 (approximately 0.55555) as large, incrementally, as the "degree" of the Celsius and Kelvin temperature scales. A temperature of 0 ^o F corresponds to approximately +255.37 degrees on the absolute Kelvin temperature scale.

To convert a Fahrenheit temperature reading to degrees Kelvin, add 459.67 and then multiply by 5/9. Conversely, multiply by 9/5 (exactly 1.8) and then subtract 459.67. To convert a Fahrenheit temperature reading to degrees Celsius, subtract 32 and then multiply by 5/9. Conversely, multiply by 9/5 and then add 32.

Also see degree Celsius , kelvin , temperature , International System of Units ( SI ), and Table of Physical Units .

21 Sep 2005