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 ≘).

Conversion calculator

Celsius scale

Kelvin scale

Fahrenheit scale

Rankine scale

Delisle scale

Newton scale

Réaumur scale

Rømer scale

Comparison values chart

Comparison of temperature scalesComparison

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.

Graphical representation

Conversion table between the different temperature units

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 change in temperature from degrees Celsius to degrees Fahrenheit, the formula is

A change in temperature given in degrees Celsius is the same value in kelvin, that is

See also

• Outline of metrology and measurement

• Degree of frost

• Conversion of units

• Gas mark

Notes and references