The degree Celsius (in symbol °C), is the unit of a temperature measurement scale, named after the Swedish astronomer Anders Celsius, who first proposed it in 1742. Some authors also use the name degree Celsius to refer to to degree Celsius.

The Celsius scale is not an absolute scale. According to the second law, the absolute temperature scale starts from the existence of absolute 0º. This condition is only met by the Kelvin and Rankine scales.

The Celsius scale is used in most parts of the world on a daily basis. However, in some states, especially the Anglo-Saxons, the Fahrenheit scale is used more frequently.

For its part, the unit of measurement of temperature of the international system of units is the kelvin.

## What Is the Definition of Celsius Scale?

The Celsius scale is defined as the temperature scale where 0 is the freezing point of water and the boiling point of water is 100 degrees Celsius.

Originally, as Celsius conceived this scale, these values were inverted: they were zero for the boiling point and one hundred for the melting point of water. However, in 1745 Jean-Pierre Christin and Carlos Linnaeus proposed reversing the scale, transforming it into the one now commonly used.

The current official definition of the Celsius scale places 0.01°C as the triple point of water and one degree as 1/273.16 of the temperature difference between the triple point of water and absolute zero.

This definition implies that the temperature difference of one degree Celsius is equal to that of one kelvin.

## Celsius Scale Formulas

Formulas to convert degrees Celsius to other units of the most important temperature scales.

Conversion from degrees Celsius to degrees Fahrenheit à °F = (9/5 × °C) + 32

Conversion from Fahrenheit to Celsius à °C = (5/9) × (°F - 32)

Conversion from Celsius to Kelvin à K = °C + 273.15

Converting Kelvin to Celsius à °C = K - 273.15

### For Example: 180 Degrees Celsius to Fahrenheit

Following the formula to convert Celsius to Fahrenheit:

(9/5 × 180ºF) + 32 = 356ºC

## What Is the Difference Between Degrees Celsius and Degrees Centigrade?

Since there are one hundred divisions between these two reference points, the original term for this system was degree centigrade or grad. In 1948, the 9th Conférence générale des poids et mesures (CR 64) officially changed the name to Celsius to remove a number of ambiguities.

The decision of the Conférence générale des poids et mesures was aimed at eliminating ambiguities and unequivocally associating the creation of the scale with Celsius. In addition, the scale was standardized to those of Kelvin (raised by lord Kelvin), Fahrenheit, Réaumur and Rankine, all of them with the name of their inventor.

Despite this, there are often people who refer to degrees centigrade as "degrees Celsius", in the same way that they use the concept centigrade scale.