Various scales are used to measure temperatures such as Celsius, Fahrenheit, and Kelvin.

Celsius and Fahrenheit are two of the common temperature scales which function very similar but differ in many ways.

Celsius, previously known as centigrade is named after a Swedish astronomer Anders Celsius. He was the one who developed that temperature scale about two years before his death.

The **melting point of ice is 0 degrees** Celsius while the boiling** point of water under a standard atmosphere is 100 degrees** Celsius.

Fahrenheit is named after Daniel Gabriel Fahrenheit, a German-Dutch physicist.

In this particular scale, **water’s freezing point is 32 degrees** Fahrenheit and the **boiling point is 212 degrees** Fahrenheit.

## Celsius

It is measured in degrees Celsius, one of the commonly used temperature units across the globe.

It is characterized by two distinct temperatures – absolute zero and the triple point of Vienna Standard Mean Ocean Water.

### What is absolute zero?

It pertains to the lowest possible temperature. Celsius is ideal for expressing temperature intervals.

### Formula

To convert of Celsius scale into the Fahrenheit scale :

°F = (^{9}/_{5}× °C) + 32

## Fahrenheit

Fahrenheit is a temperature scale where the water’s freezing point is 32 degrees and the boiling point is 212 degrees.

Fahrenheit used a mixture of ice, water, and ammonium chloride. It is termed as the **frigorific mixture** that automatically stabilizes temperature. This frigorific mixture was **used** to define 0 °**F**.

- Using this temperature scale, the water’s boiling and freezing points are 180 degrees apart.
- In the mid to late 20s, Fahrenheit was replaced by Celsius, although it remains to be the temperature scale of choice in the United States, Canada, and some of its few territories.

### Formula

To convert of Fahrenheit scale into the Celsius scale :

°C = (°F – 32) × 5/9

## Difference between Celsius and Fahrenheit

Basis for Comparison | Celsius Scale | Fahrenheit Scale |

Meaning | It is a temperature scale based on water’s freezing point at 0 degrees Celsius and water’s boiling point at 100 degrees Celsius. | It is a temperature scale based on water’s freezing point at 32 degrees Fahrenheit and water’s boiling point at 212 degrees Fahrenheit. |

Abbreviation/ denoted by | °C | °F |

Coined by/named after | It was named after an astronomer, Andres Celsius. | It was named after a physicist Daniel Gabriel Fahrenheit’. |

Water’s freezing point/melting point of ice | 0 degree Celsius, which is also the scale’s lower fixed point. | 32 degrees Fahrenheit, which is the lower fixed point of the scale. |

Water’s boiling point | 100 degrees Celsius, which is the upper fixed point of the scale. | 212 degrees Fahrenheit, which is the upper fixed point of the scale. |

Absolute zero value | -273.15 °C is the absolute zero value. | -459.67 °F is the absolute zero value. |

The average body temperature of the human | 37 °C | 98.6 °F |

Usage | The Celsius scale is used as a basis of temperature scale across the globe. | The Fahrenheit scale is widely used in the United States and some of its territories. |

Divisions | The melting, as well as the boiling points, are divided into 100 equal divisions and each division is marked at 1°C. | In Fahrenheit, the melting and boiling points are divided into 180 equal intervals and each division is marked at 1 °F. |

Formula for conversion | To convert Celsius to Fahrenheit, you have to use this formula = (°C x 1.8) + 32 = °F | To convert Fahrenheit into Celsius, you have to use this formula = (°F – 32) + 1.8 = °C |

Year introduced | 1742 A.D. | 1720 A.D. |

Lower fixed point | 0 °C | 32 °F |

Upper fixed point | 100 °C | 212 °F |

Importance | It is vital in the fields that use metric system units such as in the scientific studies. | It is the first standardized temperature scale used in the world and is widely prevalent in English-speaking countries. |

Industry of use | Scientific use/laboratory use | Non-scientific use |

### Summary of the key differences between Celsius and Fahrenheit:

- The two temperature scales, Celsius and Fahrenheit are named after two different people, an astronomer Andres Celsius and a physicist Daniel Gabriel Fahrenheit.
- The temperature scale Celsius is denoted by °C while the Fahrenheit scale is denoted by °F.
- Celsius scale was introduced in 1742 A.D. while Fahrenheit was introduced in 1720 A.D.
- Celsius and Fahrenheit differ in the temperature concept. In Celsius, the water’s freezing point is 0°C and the boiling point is 100°C. In Fahrenheit, the water’s freeing point is 32°F and the boiling point is 212°F.
- Celsius scale is widely used across the globe. On the other hand, Fahrenheit is only popular in the United States and some of its chosen territories.
- The absolute zero in the Fahrenheit scale is – 459.67 °F while on the Celsius scale, the absolute zero is – 273.15°C.
- In the human body, the average temperature in degree Celsius is 37 while the average temperature in degree Fahrenheit is 98.6.

The current health crisis (COVID-19) has caused people to be extra cautious of their health and well-being. Body temperature is one of the parameters used to check for infection.

It is a must to understand the normal body temperature, especially temperature range and units of measurement because fever is one of the common symptoms of infection.

Let us see the normal range of body temperature, definition of fever and corresponding values in Celsius and Fahrenheit as per *Harrison’s Principles of Internal Medicine, 20th Edition*: Based on studies of Healthy Individuals 18 to 40 years old.

- Mean oral temperature: 36.8° ± 0.4°C (98.2° ± 0.7°F), the level is low in the morning (6 AM) and higher in the afternoon (4 to 6 PM).
- For oral body temperature, the maximum reading in the morning is 37.2°C (98.9°F) (6 AM), and 37.7°C (99.9°F) in the afternoon (4 PM).

Fever Definition: A person has a fever is he/she has a morning temperature of>37.2°C (>98.9°F)and an afternoon temperature of>37.7°C (>99.9°F).

Please see the table below for easy reference during the celsius to fahrenheit conversions during monitoring of fever:

Celsius (°C) | Fahrenheit (°F) |

35 °C | 95 °F |

35.1 °C | 95.18 °F |

35.2 °C | 95.36 °F |

35.3 °C | 95.54 °F |

35.4 °C | 95.72 °F |

35.5 °C | 95.9 °F |

35.6 °C | 96.08 °F |

35.7 °C | 96.26 °F |

35.8 °C | 96.44 °F |

35.9 °C | 96.62 °F |

36 °C | 96.8 °F |

36.1 °C | 96.98 °F |

36.2 °C | 97.16 °F |

36.3 °C | 97.34 °F |

36.4 °C | 97.52 °F |

36.5 °C | 97.7 °F |

36.6 °C | 97.88 °F |

36.7 °C | 98.06 °F |

36.8 °C | 98.24 °F |

36.9 °C | 98.42 °F |

37 °C | 98.6 °F |

37.1 °C | 98.78 °F |

37.2 °C | 98.96 °F |

37.3 °C | 99.14 °F |

37.4 °C | 99.32 °F |

37.5 °C | 99.5 °F |

37.6 °C | 99.68 °F |

37.7 °C | 99.86 °F |

37.8 °C | 100.04 °F |

37.9 °C | 100.22 °F |

38 °C | 100.4 °F |

38.1 °C | 100.58 °F |

38.2 °C | 100.76 °F |

38.3 °C | 100.94 °F |

38.4 °C | 101.12 °F |

38.5 °C | 101.3 °F |

38.6 °C | 101.48 °F |

38.7 °C | 101.66 °F |

38.8 °C | 101.84 °F |

38.9 °C | 102.02 °F |

39 °C | 102.2 °F |

39.1 °C | 102.38 °F |

39.2 °C | 102.56 °F |

39.3 °C | 102.74 °F |

39.4 °C | 102.92 °F |

39.5 °C | 103.1 °F |

39.6 °C | 103.28 °F |

39.7 °C | 103.46 °F |

39.8 °C | 103.6 °F |

39.9 °C | 103.82 °F |

40 °C | 104 °F |

40.1 °C | 104.18 °F |

40.2 °C | 104.36 °F |

40.3 °C | 104.54 °F |

40.4 °C | 104.72 °F |

40.5 °C | 104.9 °F |

40.6 °C | 105.08 °F |

40.7 °C | 105.26 °F |

40.8 °C | 105.44 °F |

40.9 °C | 105.62 °F |

41 °C | 105.8 °F |

41.1 °C | 105.98 °F |

41.2 °C | 106.16 °F |

41.3 °C | 106.34°F |

41.4 °C | 106.52 °F |

41.5 °C | 106.7 °F |

41.6 °C | 106.88 °F |

41.7 °C | 107.06 °F |

41.8 °C | 107.24 °F |

41.9 °C | 107.42 °F |

42 °C | 107.6 °F |

42.1 °C | 107.78 °F |

42.2 °C | 107.96 °F |

42.3 °C | 108.14 °F |

42.4 °C | 108.32 °F |

42.5 °C | 108.5 °F |

42.6 °C | 108.68 °F |

42.7 °C | 108.86 °F |

42.8 °C | 109.04 °F |

42.9 °C | 109.22 °F |

43 °C | 109.4 °F |

### Conclusion

- The Celsius and Fahrenheit scales are the two parameters commonly used to measure temperature.
- However, many would consider Celsius as a convenient and easy way to measure temperature.
- While there are many differences between Celsius and Fahrenheit, one thing is for sure, they both measure the correct temperature and each of them has usefulness in various industries.
- Celsius is a part of the metric system, which was originally known as the centigrade scale.
- Fahrenheit is mostly preferred in the United States and some of its territories.

**References:**

*https://microbenotes.com/celsius-scale-vs-fahrenheit-scale/**https://biodifferences.com/difference-between-celsius-and-fahrenheit.html**https://sciencing.com/degree-between-celsius-vs-fahrenheit-8060500.html**http://abyss.uoregon.edu/~js/glossary/temperature_scale.html**https://www.diffen.com/difference/Celsius_vs_Fahrenheit**https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Quantifying_Nature/Temperature_Basics**https://www.infoplease.com/math-science/weights-measures/fahrenheit-and-celsius-centigrade-scales**https://courses.lumenlearning.com/boundless-physics/chapter/temperature-and-temperature-scales/**https://byjus.com/physics/celsius-and-fahrenheit-difference/**https://differencecamp.com/celsius-vs-fahrenheit-differences/*