Temperature is a property that helps measure the degree of hotness or coldness of an object. Celsius and Kelvin are both temperature scales that are part of the International System of Units (SI) for the measurement of temperature.

Celsius is symbolized by °C (degree Celsius) while K symbolizes kelvin.

During calculations, the interconversion between Celsius and Kelvin may deem necessary.

So, lets read further to understand how to convert Celsius to Kelvin and vice versa.

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Suggested read – How to Convert Celsius to Fahrenheit

What is Celsius?

The Celsius scale was also previously known as the centigrade scale.

It is one of the temperature scales used in the SI unit system along with the Kelvin scale.

The symbol for Celsius is °C (degrees Celsius).

It is used in most of the countries worldwide except the US and Liberia. These countries use the Fahrenheit scale.

In 1954, the definition of Celsius changed and was related to the Kelvin scale. At absolute zero (0K), the temperature is precise -273.15°C on the Celsius scale.

At 1 atm pressure (that is, standard atmospheric pressure), the boiling point of water is 100°C, and the freezing point of water is 0°C which formed the basis for the Celsius scale before 1954.


Formerly, the Celsius scale was known as the centigrade scale. The word ‘centigrade’ was derived from two Latin words: centum which means hundred and gradus which means steps.

In 1948, it was renamed after Anders Celsius to honor him.


  • In lots of countries, the Celsius scale is used while reporting the weather
  • Celsius is also conveniently used in the fields of research as 1°C change in temperature corresponds to a 1K difference.

What is Kelvin?

Kelvin is a thermodynamic temperature scale. At absolute zero, (that is, 0K) all thermal activity stops. The absolute zero forms the basis for the Kelvin scale.

The triple point of water, a temperature at which all three states of eater exist in equilibrium, is precisely 273.16 K and this is also used as one of the basis for defining the Kelvin scale.

The symbol for Kelvin is K.

Absolute zero is -273.15°C on the Celsius scale. That way, 0K = -273.15°C


Kelvin scale is named after the engineer and physicist William Thomson, I Baron Kelvin (1824-1907) from the Glasgow University who had first written about an “absolute temperature scale.”


  • In physical sciences, the Kelvin scale is used primarily for measurement of temperature.
  • While expressing the magnitude of change in temperatures, the Kelvin scale is preferred.
  • Kelvin scale is used along with the Celsius scale for measurement of temperature changes.
  • Kelvin is used as the basis for color temperatures of various bodies. For example, below 4000 K, the object appears red.

How to Convert Celsius to Kelvin?

To convert Celsius to Kelvin, the following formula is used,

T [K] = T [°C] + 273.15

To convert Celsius to Kelvin, add 273.15 to the temperature value in Celsius.

For example,

You are given the temperature of a body at 25° C, and for further calculations, you need it in kelvins. Substituting the values in the formula above,

T [K] = 25 + 273.15

= 298.15 K

Hence, the temperature of the body is 298.15 K.

Popular Conversions

Celsius (°C)Kelvin (K)

How to Convert Kelvin to Celsius?

To convert Kelvin to Celsius, the following formula is used,

T [°C] = T [K] – 273.15

For the conversion of Kelvin into Celsius, subtract 273.15 from the Kelvin value of temperature.

For example,

The temperature of a certain body is given as 300 K. To convert this into Celsius,

T [°C] = 300 – 273.15

= 26.85 ~ 27° C

Therefore, the temperature of a body at 300 K is approximately 27° C.

Some interesting Facts about celsius and kelvin

  • Each degree in the Kelvin scale is equal to a degree in the Celsius scale.
  • The average body temperature for humans is usually 37°
  • Absolute zero is not possible to attain.
  • The lowest recorded temperature in the universe is 3 K which is observed in space.
  • The highest temperature recorded on earth is 57.8° C in Libya in September of 1922.
  • The lowest temperature ever recorded on earth is -89.2° C in Antarctica.
Celsius and Kelvin are temperature scales that are part of the International System of Units (SI). Add 273.15 to Celsius to get in Kelvin.