# Temperature Conversion

Round:
Celsius
Fahrenheit
Kelvin
Rankine

Freezing, Boiling and Absolute Zero Temperatures:

The temperature conversions are all based on the differences between the freezing & the boiling point of water and the defined abosolute zero temperatures between the scales.

Freezing Temperatures:

Celsius = 0 °C
Fahrenheit = 32 °F
Kelvin = 273.15 K
Rankine = 491.67 °Rankine
Reaumur = 0 °Reaumur

Boiling Temperatures:

Celsius = 100 °C
Fahrenheit = 212 °F
Kelvin = 373.15 K
Rankine = 671.67 °Rankine
Reaumur = 80 °Reaumur

Absolute Zero Temperatures:

Celsius = -273.15 °C
Fahrenheit = -459.67 °F
Kelvin = 0 K
Rankine = 0 °Rankine

The Kelvin and Reaumur are based on Celsius scale and the Rankine is based on Fahrenheit scale. To convert between the temperature units these are commonly used:

1.8: Celsius to Fahrenheit ratio. For each Celsius degree there are 1.8 Fahrenheit degrees and it is calculated by dividing the difference between the boiling and the freezing points for each of these temperature scales, (212 °F - 32 °F) / (100 °C - 0 °C) = 1.8 .

32: The difference between the freezing point of Fahrenheit (32) and the freezing point of Celsius (0).

Here is a comparision of temeperature scales in a table.

How to convert from Celsius to Fahrenheit?

To convert from degrees Celsius to Fahrenheit, multiply the Celsius by 1.8 and add 32.

Fahrenheit = Celsius × 1.8 + 32

You may access more information about how to convert from Celsius to Fahrenheit and access the tables, please check Celsius to Fahrenheit page.

How to convert from Fahrenheit to Celsius?

To convert from Fahrenheit to Celsius degrees, fist subtract 32, then divide the result by 1.8 ratio.

Celsius = (Fahrenheit - 32) ÷ 1.8

You may access more information about how to convert from Fahrenheit to Celsius and access the tables, please check Fahrenheit to Celsius page.

How to convert between Celsius and Kelvin?

To convert Celsius to Kelvin, add 273.15 to Celsius because the absolute zero is theoretically possible at 0 Kelvin or -273.15 °C.

Kelvin = Celsius + 273.15

Celsius = Kelvin - 273.15

You may access more information about how to convert from Celsius to Kelvin and access the tables, please check Celsius to Kelvin page.

How to convert between Fahrenheit and Kelvin?

To convert Fahrenheit to Kelvin, add 459.67 to Fahrenheit and divide by 1.8.

Kelvin = (Fahrenheit + 459.67) ÷ 1.8

Fahrenheit = (Kelvin × 1.8) - 459.67

You may access more information about how to convert from Fahrenheit to Kelvin and access the tables, please check Fahrenheit to Kelvin page.

How to convert between Celsius and Rankine?

The absolute zero is "0" for Rankine scale as it is in the Kelvin scale but Rankine is based on Fahrenheit rather than the Celsius scale. To convert from Celsius to Rankine, multiply the Celsius value by 1.8 ratio and add 32 (freezing point difference between Celsius and Fahrenheit) and add 459.67 since -459.67 the the absolute zero temperature for Fahrenheit.

Rankine = Celsius × 1.8 + 32 + 459.67

To convert from Rankine to Celsius, you have to do the opposite.

Celsius = (Rankine - 32 - 459.67) / 1.8

How to convert between Fahrenheit and Rankine?

Because the Rankine scale is based on the Fahrenheit scale, to convert from Fahrenheit to Rankine, all we have to do is to add the difference between the absolute zero temperatures of these two scales.

Rankine = Fahrenheit + 459.67

To convert from Rankine to Fahrenheit, you have to do the opposite.

Fahrenheit = Rankine - 459.67

How to convert between Kelvin and Rankine?

The Kalvin is based on the Celsius scale but the Rankine is based on the Fahrenheit scale. To convert from Kelvin to Rankine, multiply the Kelvin by 1.8 ratio.

Rankine = Kelvin × 1.8

To convert from Rankine to Kelvin, you have to do the opposite.

Kelvin = Rankine ÷ 1.8

How to convert between Celsius and Reaumur?

The Reaumur scale is based on the Celsius scale where the freezing point of water is "0" and the boiling point of water is defined as "80" degrees. To convert from Celsius to Reaumur, multiply the Celsius value by 0.8.

Reaumur = Celsius × 0.8

To convert from Reaumur to Celsius, you have to do the opposite.

Celsius = Reaumur ÷ 0.8

or

Celsius = Reaumur × 1.25

How to convert between Fahrenheit and Reaumur?

The Reaumur scale is based on the Celsius scale where the freezing point of water is "0" and the boiling point of water is defined as "80" degrees. To convert from Fahrenheit to Reaumur, subtract 32 from the Fahrenheit value and divide it by 2.25, since 1 Reaumur = 2.25 Fahrenheit.

Reaumur = (Fahrenheit - 32) ÷ 2.25

To convert from Reaumur to Fahrenheit, you have to do the opposite.

Fahrenheit = (Reaumur × 2.25) + 32

How to convert between Kelvin and Reaumur?

The Kelvin and the Reaumur scales are based on the Celsius scale. To convert from Kelvin to Reaumur, subtract 273.15 from the Kelvin value and multiply it by 0.8, since 1 Reaumur = 1.25 Celsius.

Reaumur = (Kelvin - 273.15) × 0.8

To convert from Reaumur to Kelvin, you have to do the opposite.

Kelvin = (Reaumur ÷ 0.8) + 273.15

How to convert between Rankine and Reaumur?

The Rankine is based on the Fahrenheit scale and the Reaumur scale is based on the Celsius scale.

Reaumur = (Rankine - 32 - 459.67) ÷ 2.25

To convert from Reaumur to Rankine, you have to do the opposite.

Rankine = (Reaumur × 2.25) + 32 + 459.67