C Program to Convert Fahrenheit to Celsius - Formula & Function

Convert Fahrenheit to Celsius Using Formula

#include <stdio.h>
int main() {
    float fahrenheit, celsius;
    printf("Enter temperature in Fahrenheit: ");
    scanf("%f", &fahrenheit);
    celsius = (fahrenheit - 32) * 5 / 9;
    printf("Temperature in Celsius = %.2f\n", celsius);
    return 0;
}
Enter temperature in Fahrenheit: 100
Temperature in Celsius = 37.78
        

The Celsius temperature is computed by subtracting 32 from the Fahrenheit value and multiplying the difference by 5/9. This formula works for any numeric input.

Convert Fahrenheit to Celsius Using a Function

#include <stdio.h>
float fahrenheit_to_celsius(float f) {
    return (f - 32.0f) * 5.0f / 9.0f;
}
int main() {
    float f;
    printf("Enter temperature in Fahrenheit: ");
    scanf("%f", &f);
    printf("Temperature in Celsius = %.2f\n", fahrenheit_to_celsius(f));
    return 0;
}
Enter temperature in Fahrenheit: 50
Temperature in Celsius = 10.00
        

Encapsulating the conversion in a separate function improves reusability. The function subtracts 32 from the input, multiplies by 5/9 and returns the result.

Sai Kishore Randhi, author
About the author

Sai Kishore Randhi

Embedded systems, VLSI, and chip design

Sai Kishore writes about embedded systems, VLSI, chip design, and the programming concepts behind modern hardware.

View LinkedIn profile ↗