Rankine - AbsoluteAstronomy.com

**Rankine temperature conversion formulae**
	from Rankine	to Rankine
Celsius Celsius Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...	[°C] = ([R] − 491.67) × ⁵⁄₉	[R] = ([°C]+273.15) × ⁹⁄₅
Fahrenheit Fahrenheit Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...	[°F] = [R] - 459.67	[R] = [°F] + 459.67
Kelvin Kelvin The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...	[K] = [R] × ⁵⁄₉	[R] = [K] × ⁹⁄₅
For temperature intervals rather than specific temperatures, 1 R = 1 °F = ⁵⁄₉ °C = ⁵⁄₉ K Comparisons among various temperature scales Temperature conversion formulas This is a compendium of temperature conversion formulæ and comparisons.-Celsius :The simple approximation [°F] = [°C] × 2 + 30 works well within the range of normal weather temperatures, underestimating by 6°F at −20°C and over by 4°F at 30°C.-Comparison:-Comparison of temperature scales:...

Rankine is a thermodynamic (absolute) temperature

Thermodynamic temperature

Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is an "absolute" scale because it is the measure of the fundamental property underlying temperature: its null or zero point, absolute zero, is the...

scale named after the Scottish engineer

Engineer

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

and physicist

Physicist

A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

William John Macquorn Rankine

William John Macquorn Rankine was a Scottish civil engineer, physicist and mathematician. He was a founding contributor, with Rudolf Clausius and William Thomson , to the science of thermodynamics....

, who proposed it in 1859. (The Kelvin

Kelvin

The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...

scale was first proposed in 1848.)

The symbol for degrees Rankine is R (or Ra if necessary to distinguish it from the Rømer

Rømer scale

Rømer is a temperature scale named after the Danish astronomer Ole Christensen Rømer, who proposed it in 1701.In this scale, the zero was initially set using freezing brine. The boiling point of water was defined as 60 degrees...

and Réaumur scales). Zero on both the Kelvin and Rankine scales is absolute zero

Absolute zero

Absolute zero is the theoretical temperature at which entropy reaches its minimum value. The laws of thermodynamics state that absolute zero cannot be reached using only thermodynamic means....

, but the Rankine degree is defined as equal to one degree Fahrenheit

Fahrenheit

Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...

, rather than the one degree Celsius

Celsius

Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

used by the Kelvin scale. A temperature of −459.67 °F is exactly equal to 0 R.

Some engineering fields in the U.S.

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

measure thermodynamic temperature using the Rankine scale. However, throughout the entire scientific world thermodynamic temperature is measured in Kelvin. The US National Institute of Standards and Technology

National Institute of Standards and Technology

The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...

does not recommend using degrees Rankine in NIST publications.

Some key temperatures relating the Rankine scale to other temperature scales are shown in the table below.

	Kelvin	Celsius	Fahrenheit	Rankine
Absolute zero (by definition)	0 K	−273.15 °C	−459.67 °F	0 R
Freezing point of brine (by definition)	255.37 K	−17.78 °C	0 °F	459.67 R
Freezing point of water	273.15 K	0 °C	32 °F	491.67 R
Triple point Triple point In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases of that substance coexist in thermodynamic equilibrium... of water (by definition)	273.16 K	0.01 °C	32.018 °F	491.688 R
Boiling point Boiling point The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid.... of water	373.1339 K	99.9839 °C	211.97102 °F	671.64102 R

See also