Kelvin, Celsius, Fahrenheit and Rankine Converter

Less commonly used temperature scales such as Kelvin and Rankine can be converted to Celsius or Fahrenheit with our multiple unit converter.

To use this converter just type the known unit into its box to convert to the other units.

Kelvin Celsius Fahrenheit Rankine
K = °C = °F = °R

Conversion Formulae

The conversion formulae to convert between Kelvin, Celsius, Fahrenheit and Rankine are as follows:

Conversions to Kelvin

  • K = °C + 273.15
  • K = (°F + 459.67) x 5/9
  • K = °R x 5/9

Conversions to Celsius

  • °C = K - 273.15
  • °C = (°F - 32) x 5/9
  • °C = (°R - 491.67) x 5/9

Conversions to Fahrenheit

  • °F = (K x 9/5) - 459.67
  • °F = (°C x 9/5) + 32
  • °F = °R - 459.67

Conversions to Rankine

  • °R = K x 9/5
  • °R = (°C + 273.15) x 9/5
  • °R = °F + 459.67


The Kelvin and Rankine temperature scales were created in response to the need for and absolute thermometric scale, both have there zero point at absolute zero and progress from that point.

Kelvin is one of the seven base units of the SI system of units and a temperature interval of 1K is the same as a temperature interval of 1°C. The Rankine temperature scale has a temperature interval of 1°R being equivalent to 1°F.

Effectively Celsius is to Kelvin as Fahrenheit is to Rankine. The Rankine scale is now rarely used as most scientific work, even in countries that still use the Fahrenheit scale for day to day measurement of temperature, is now done in Kelvin.


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