Conversion of scales of temperature

This is a collection of temperature conversion formulas and comparisons among eight different temperature scales, several of which have long been obsolete.

Temperatures on scales that either do not share a numeric zero or are nonlinearly related cannot correctly be mathematically equated (related using the symbol =), and thus temperatures on different scales are more correctly described as corresponding (related using the symbol ≘).

Comparison of temperature scales
* Normal human body temperature is 36.8 °C ±0.7 °C, or 98.2 °F ±1.3 °F. The commonly given value 98.6 °F is simply the exact conversion of the nineteenth-century German standard of 37 °C. Since it does not list an acceptable range, it could therefore be said to have excess (invalid) precision.

Some numbers in this table have been rounded.

Converting units of temperature differences
Converting units of temperature differences (also referred to as temperature deltas) is not the same as converting absolute temperature values, and different formulae must be used.

To convert a delta temperature from degrees Fahrenheit to degrees Celsius, the formula is {ΔT}°F = $9⁄5${ΔT}°C.

To convert a delta temperature from degrees Celsius to kelvin, it is 1:1 ({ΔT}°C = {ΔT}K).