Temperature is a parameter to measure the intensity of the hotness or coldness a body (or an object). It is one of the most important physical attributes for different scientific researches, laboratory experiments and other branches of physics, science, and technology.

Celsius and Fahrenheit are two of the most popular units of the temperature measurement. And hence it is utterly essential to know how to convert Fahrenheit to Celsius and vice-versa.

For example, in the Fahrenheit scale of temperature, the freezing point of water is at 32°, and the boiling point of the water is at 212°. In the Celsius scale for temperature measurement, 0 degrees and 100 degrees are the freezing and boiling points of water respectively.

Isn’t it would be great to know how to convert them?

Conversion calculator

You can convert a temperature from Fahrenheit to Celsius very quickly using the conversion calculator given below

Conversion formula of Fahrenheit to Celsius

The conversion formula of T degree Fahrenheit (T °F) to T degree Celsius (T °C) is

T (°C) = (T(°F) – 32) × 5/9

Example

Incase you want to convert 90° F to Celsius, using the conversion formula as listed above,

90 °F = (90- 32) × 5/9 °C=32.23 °C
Similarly, to convert freezing point of water which is 32 °F, use the same formula

32 °F = (32- 32) × 5/9 °C= 0 °C

which anyway we should be aware of.

Conversion formula of Celsius to Fahrenheit

The conversion formula of T degree Celsius (T °C) to T degree Fahrenheit (T °F) is as shown below.

T (°F) = T (°C) × 9/5 + 32

Example

Let’s say you get a requirement of converting 75 °C in Fahrenheit. Using the Conversion formula of Celsius to Fahrenheit we get,

75 °C = (75× 9/5+ 32) °F= 167°F

What is Celsius?

The Celsius scale is the scale to measure temperature in the SI units (International System of Units). This is a widespread unit to measure temperature all over the world except Liberia and the United States.

The Celsius scale is used more commonly than the Fahrenheit scale in the scientific and technical fields. In the standard condition (at the sea level and one atmospheric pressure) the freezing and boiling temperatures of water are 0 and 100 respectively in this scale of measurement.

This scale uses the unit named degree Celsius (°C).

The international definition of the Celsius scale is based on the base unit of the temperature of physics called Kelvin (K).
0 K = −273.15 °C

Origin

The former name of the Celsius scale was centigrade scale the origin of which is the Latin word centum meaning one hundred.

The name ‘Celsius’ has come from the name of the Swedish astronomer Anders Celsius as he   (1701–1744)     invented a similar scale much before.

The unit °C defines a particular temperature or a difference between two temperatures on this scale.

Usages

  • Celsius scale is the most common unit to measure temperature in all kind of scientific or laboratory experiments.
  • To denote the freezing (0 Celsius) and boiling points (100 Celsius) of water we use this unit more frequently than any other scale of the unit.
  • Scientists find this scale most suitable for all their research work as the temperature change of 1 °C is equal to the same of 1 K.

What is Fahrenheit?

The Fahrenheit is a scale of the unit to measure the temperature, where the freezing point of water is 32° F, and the boiling point of water is 212° F. Interestingly, these two points have a 180 ° difference in this scale.

This scale uses the unit degree Fahrenheit (°F).

Origin

The German-born Scientist and Physicist Daniel Gabriel Fahrenheit invented the Fahrenheit temperature scale at first in 1724.

He used a mixture of water, ice, and ammonium chloride and put the thermometer in this mixture to determine the lowest point of this temperature scale. This mixture is an example of the frigorific mixture (A mixture to obtain equilibrium temperature in scientific experiments).

By this experiment, he determined the lowest point of temperature as 0 °F (−17.78 °C).

Later he re-calibrated that Fahrenheit scale using the melting point of ice and the temperature of an average human body.

The definition and calibration of the Fahrenheit scale have been changed and evolved through the years after that until the present one has invented. The concept of the freezing point of water came later than that.

The United States including its territories and the other associated states use this scale to measure temperature.

Usages

  • For the weather and temperature reports, this unit is used widely (Especially in the U.S).
  • In various fields like cooking, medical etc. the temperature is expressed in this unit.
  • In many countries, it is used as a supplementary scale to precisely measure the temperature.
  • For the body temperature measurement, this scale is the most common one. The average human body temperature is 98.6 degrees Fahrenheit.

Quick look up – Fahrenheit to Celsius conversion table

Degree Fahrenheit

Degree Celsius

0

-17.78

10

-12.22

20

-6.67

30

-1.11

32

0

40

4.44

50

10.00

60

15.56

70

21.11

80

26.67

90

32.22

100

37.78

Interesting facts about Fahrenheit and Celsius scales

  • The lowest possible temperature in the thermodynamic temperature (The absolute and exact measure of temperature in physics) is called the absolute zero. Absolute zero is equal to −273.15 °C or −459.67 °F.
  • The Rankine temperature scale (named after the physicist William John Macquorn Rankine) was based on the Fahrenheit temperature.
  • The absolute zero of temperature is also called the triple point of water. In this temperature, all three states (solid, liquid and gas) of a substance exist in an equilibrium condition.
  • The temperature of the surface of the Sun is about 5,600 Celsius (10,000 Fahrenheit). 
  • The human body temperatures above 104 °F (40 °C) can be fatal and life-threatening. In normal condition, the oral temperature is 97.3° to 98.8° F.
  • 52-year-old Willie Jones of Atlanta (1980) holds the Guinness Book of World Records honor for surviving even after having the highest recorded body temperature (115 degrees Fahrenheit) in this world.