Temperature Converters - Celsius, Fahrenheit, Kelvin, Rankine and Reaumur Converters

This temperature converter can be used to convert from one common temperature unit to another, Celsius, Fahrenheit, Kelvin, Rankine and Reaumur. Select any temperature unit to input the value. Click the convert button to get the values in other temperature units.

Temperature unit of measure converter

Knowledge of converter

The Celsius scale, previously known as the centigrade scale, is a temperature scale used by the International System of Units (SI). As an SI derived unit, it is used by all countries in the world, except the United States, and Liberia. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale. The degree Celsius (symbol: °C) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature interval, a difference between two temperatures or an uncertainty.

The Fahrenheit scale is a temperature scale based on one proposed in 1724 by Dutch-German-Polish physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his scale exist. The lower defining point, 0 °F, was established as the temperature of a solution of brine made from equal parts of ice, water and salt (ammonium chloride). Further limits were established as the melting point of ice (32 °F) and his best estimate of the average human body temperature (96 °F, about 2.6 °F less than the modern value due to a later redefinition of the scale). The scale is now usually defined by two fixed points: the temperature at which water freezes into ice is defined as 32 °F, and the boiling point of water is defined to be 212 °F, a 180 °F separation, as defined at sea level and standard atmospheric pressure

The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. The kelvin (symbol: K) is the base unit of temperature in the International System of Units (SI). The kelvin is defined as the fraction ​1⁄273.16 of the thermodynamic temperature of the triple point of water (exactly 0.01 °C or 32.018 °F).[1] In other words, it is defined such that the triple point of water is exactly 273.16 K.

The symbol for degrees Rankine is °R (or °Ra if necessary to distinguish it from the Rømer and Réaumur scales). By analogy with kelvin, some authors term the unit rankine, omitting the degree symbol. Zero on both the Kelvin and Rankine scales is absolute zero, but a temperature difference of one Rankine degree is defined as equal to one Fahrenheit degree, rather than the Celsius degree used on the Kelvin scale. Thus, a temperature of 0 K (−273.15 °C; −459.67 °F) is equal to 0 °R, and a temperature of−458.67 °F equal to 1 °R.

The Réaumur scale French: [ʁe.o.myːʁ] (°Ré, °Re, °r), also known as the "octogesimal division", is a temperature scale for which the freezing and boiling points of water are defined as 0 and 80 degrees respectively. The scale is named for René Antoine Ferchault de Réaumur, who first proposed a similar scale in 1730.

Fahrenheit temperature conversion formulae

from Fahrenheitto Fahrenheit
Celsius[°C] = ([°F] − 32) × ​59[°F] = [°C] × ​95 + 32
Kelvin[K] = ([°F] + 459.67) × ​59[°F] = [K] × ​95 − 459.67
Rankine[°R] = [°F] + 459.67[°F] = [°R] − 459.67
For temperature intervals rather than specific temperatures,
1 °F = 1 °R = ​59 °C = ​59 K

Kelvin temperature conversion formulae

from kelvinsto kelvins
Celsius[°C] = [K] − 273.15[K] = [°C] + 273.15
Fahrenheit[°F] = [K] × ​95 − 459.67[K] = ([°F] + 459.67) × ​59
Rankine[°R] = [K] × ​95[K] = [°R] × ​59
For temperature intervals rather than specific temperatures,
1 K = 1 °C = ​95 °F = ​95 °R

Rankine temperature conversion formulae

from Rankineto Rankine
Celsius[°C] = ([°R] − 491.67) × ​59[°R] = ([°C] + 273.15) × ​95
Fahrenheit[°F] = [°R] − 459.67[°R] = [°F] + 459.67
Kelvin[K] = [°R] × ​59[°R] = [K] × ​95
For temperature intervals rather than specific temperatures,
1 °R = 1 °F = ​59 °C = ​59 K

Réaumur temperature conversion formulae

from Réaumurto Réaumur
Celsius[°C] = [°Ré] × ​54[°Ré] = [°C] × ​45
Fahrenheit[°F] = [°Ré] × ​94 + 32[°Ré] = ([°F] − 32) × ​49
Kelvin[K] = [°Ré] × ​54 + 273.15[°Ré] = ([K] − 273.15) × ​45
Rankine[°R] = [°Ré] × ​94 + 491.67[°Ré] = ([°R] − 491.67) × ​49
For temperature intervals rather than specific temperatures,
1 °Ré = 1.25 °C = 2.25 °F

Temperature unit conversion tables

Celsius ()Kelvin (K)Fahrenheit (οF)Rankine (οRa)Reaumur (oR)