C Program to Convert Celsius to Fahrenheit – Coding Connect

Before going to the program first let us see how to convert Celsius to Fahrenheit?

To convert from Celsius to Fahrenheit: first multiply by 180/100, then add 32.

But 180/100 can be simplified to 9/5, so this is the easiest way:

°C to °F: Multiply by 9, then divide by 5, then add 32

So now we can write a formula like this:

Celsius to Fahrenheit:   (°C × 9/5) + 32 = °F

Other Method: Use 1.8 instead of 9/5

9/5 is equal to 1.8, so we can also use this method.

Thus the formula is:

Celsius to Fahrenheit:   °C × 1.8 + 32 = °F

Example: Convert 41° Celsius to Fahrenheit

First: 41° × 1.8 = 73.8
Then: 73.8 + 32 = 105.8° F

Program code to convert Celsius to Fahrenheit in C:

#include<conio.h> void main()
{ float cels,fah; clrscr(); printf("Enter the temperature in Celsius:"); scanf("%f",&cels); fah=(1.8*cels)+32; printf("nConverted Temperature is %.2f%cF",fah,248); getch();


  • First the computer reads the temperature in Celsius from the user and stores it in the “cels” variable using the following lines:
printf("Enter the temperature in Celsius:");

 Note: %f is used to read the floating-point value (decimal value).

  • Then using the formula the Fahrenheit value is calculated and stored in the “fah” variable using the following line:
  • Finally the Fahrenheit value is printed on the screen using the following line:
printf("nConverted Temperature is %.2f%cF",fah,248);

Note: %.2f is used to print the floating-point value with only 2 decimal places,

             %c is used to print a character and

     248 is the ASCII value of the character ” º “(degree).


Celsius to Fahrenheit