Fahrenheit to Celsius (°F to °C) | Formula , Conversion and Examples

Fahrenheit to Celsius converter is a free online tool prepared at Geeksforgeeks to easily convert the Fahrenheit value of temperature to the Celsius value of temperature.

Steps to use Fahrenheit to Celsius Converter

Step 1: Enter Temperature Value

• Type a temperature value in either the Fahrenheit (°F) or Celsius (°C) input field.

Step 2: Automatic Conversion

• The tool will instantly convert the value to the other unit and display the result.

Step 3: Use Quick Temperature Buttons

• Click preset buttons like Freezing (32°F), Body Temperature (98.6°F), Room Temperature (70°F), or Boiling (212°F) for quick conversions.

Step 4: View Conversion Details

• The converter will show a small information box explaining the exact converted value.

Step 5: Check the Formula

• The formula (°F − 32) × 5/9 = °C is displayed at the bottom for reference.

Fahrenheit Scale

• Fahrenheit is a scale of temperature.
• Its unit is the degree Fahrenheit (°F).
• This unit is named after physicist Daniel Gabriel Fahrenheit, who first proposed this temperature scale in 1724. On the Fahrenheit scale, the water freezes at 32°F and boils at 212°F under normal conditions.
• Fahrenheit is also the U.S. customary measurement unit of temperature.

Celsius Scale

• Celsius is also a scale of temperature.
• Its unit is the degree Celsius (°C).
• This unit was named after astronomer Anders Celsius in 1948 . On the Celsius scale, the water freezes at 0°C and boils at 100°C under normal conditions.

Fahrenheit to Celsius(°F to °C) Conversion Formula

To convert Fahrenheit to Celsius, the formula used is °C = 5/9(°F - 32). Using Fahrenheit to Celsius formula (F to C formula), the temperature in Fahrenheit can easily be converted into Celsius. The Celsius to Fahrenheit conversion is added in the image below:

Example: Convert 80 Fahrenheit to Celsius.

Given Temperature = 80 °F

Using the Formula, °C = 5/9(°F - 32)
C = 5/9(80 - 32)
C = 26.67°C

Hence, 80°F = 26.67°C

As mentioned above, the freezing point and boiling point in the Fahrenheit scale are 32°F and 212°F, respectively. Similarly, for Celsius, it is 0°C and 100°C, respectively.

Let's assume a graph in which the X-axis corresponds to Fahrenheit and the Y-axis corresponds to Celsius, the graph for the same is added below:

Now to calculate the slope of this graph we use the Slope Formula(m) = Δy/Δx

Consider,

y₁ = 0, y₂ = -17.78

• Δy = y₂ - y₁
• Δy = -17.78

x₁ = 32, x₂ = 0

• Δx = x₂ - x₁
• Δx = -32

Slope (m) = Δy/Δx 

= -17.78/-32 
= 5/9

Using the Slope-Line Form, of Line

°C = 5/9(°F - 32)

Celsius to Fahrenheit Formula

In order to convert Celsius to Fahrenheit, a specific formula is used. Celsius to Fahrenheit formula or C to F is obtained from the above given Fahrenheit to Celsius formula, and hence, Celsius to Fahrenheit formula will be °F = 9/5°C + 32. By using the formula, we can convert any temperature given in Celsius to Fahrenheit. 

Example: Convert 35.5 Celsius to Fahrenheit.

Solution:

Given Temperature = 35.5 °C

°F = 9/5°C + 32
°F = 9/5 (35.5) + 32
°F = 63.9 + 32
°F = 95.9

How to Convert Fahrenheit to Celsius

Fahrenheit to Celsius Conversion is achieved using the steps added below:

Step 1: First of all, whatever value is given in Fahrenheit, subtract 32 from the value.

Step 2: Now the value should be multiplied by 5.

Step 3: The last step is to divide the value obtained in step 2 by 9.

Fahrenheit to Celsius Conversion Shortcut

A simplified method for converting Fahrenheit (°F) to Celsius (°C) involves subtracting 30 from the Fahrenheit temperature and then dividing the result by 2 to obtain an approximate Celsius value.

The formula for this approximation is:

Celsius (approx.) = (Fahrenheit − 30)/2​

Example: Suppose we have a Fahrenheit temperature of 86°F. Using the simplified approximation method:

Celsius (approx.) = (86−30)/2 ​= 56/2 = 28°C

So, according to the approximation, 86°F is approximately equal to 28°C.

Fahrenheit to Celsius (°F to °C) Conversion Table

A table for temperature can be formed for any temperature unit using the temperature conversion formula. Here, the above formula is used to make the table. Temperature values converted from Fahrenheit to Celsius are shown below:

Fahrenheit to Celsius to Kelvin Chart

The following chart provides conversions between Fahrenheit, Celsius, and Kelvin temperature scales:

Solved Questions on Fahrenheit to Celsius Conversion (°F to °C)

Question 1: Convert 80 Fahrenheit to Celsius (F to C).

Solution: 

Given Temperature = 104 °F

Using F to C formula, °C = 5/9(°F - 32)
C = 5/9(104 - 32)
C = 40 °C

Hence, 104 °F = 40 °C

Question 2: Convert 75 Fahrenheit to Celsius (F to C).

Solution: 

Given Temperature = 75 °F

Using F to C formula, °C = 5/9(°F - 32)
C = 5/9(75 - 32)
C = 23.9°C

Hence, 75 °F = 23.9 °C

Question 3: Convert 100 Fahrenheit to Celsius (F to C).

Solution: 

Given Temperature = 100 °F

Using F to C formula, °C = 5/9(°F - 32)
C = 5/9(100 - 32)
C = 37.77°

Hence, 100°F = 37.77°C

Question 4: Convert 108 Fahrenheit to Celsius (F to C).

Solution: 

Given Temperature = 108 °F

Using F to C formula, °C = 5/9(°F - 32)
C = 5/9(108 - 32)
C = 42.22°

Hence, 108°F = 42.22°C

Question 5: Convert 98.6 Fahrenheit to Celsius (F to C).

Solution:

Given Temperature = 98.6 °F

Using F to C formula, °C = 5/9(°F - 32)
C = 5/9(98.6 - 32)
C = 37°

Hence, 98.6°F = 37°C

Practice Questions on Fahrenheit to Celsius (F to C)

Question 1: Convert 6 Fahrenheit to Celsius (°F to °C).

Question 2: Convert 1.5 Fahrenheit to Celsius (°F to °C).

Question 3: Convert 2.5 Fahrenheit to Celsius (°F to °C).

Question 4: Convert 54 Fahrenheit to Celsius (°F to °C).

Question 5: What is 9 Fahrenheit to Celsius (°F to °C)?