Calculate the Power of a Number in C Program

Example to read how to calculate the power of a number if the exponent is an integer. Also you will learn to compute the power using pow() function.

The program below takes two integers from the user (a base number and an exponent) and calculates the power.

For example: In case of 23

• 2 is the base number
• 3 is the exponent
• And, the power is equal to 2*2*2

Example N. 1: Power of a Number Using while Loop

#include <stdio.h>
int main()
{
    int base, exponent;

    long long result = 1;

    printf("Enter a base number: ");
    scanf("%d", &base);
    printf("Enter an exponent: 4");
    scanf("%d", &exponent);

    while (exponent != 0)
    {
        result *= base;
        --exponent;
    }

    printf("Answer = %lld", result);

    return 0;
}

Output

v
Enter a base number: 3
Enter an exponent: 4
Answer = 81

The above technique works only if the exponent is a positive integer.

If you need to find the power of a number with any real number as an exponent, you can use pow() function. 

Example N. 2: Power Using pow() Function

#include <stdio.h>
#include <math.h>

int main()
{
    double base, exponent, result;

    printf("Enter a base number: ");
    scanf("%lf",&base);

    printf("Enter an exponent: ");
    scanf("%lf",&exponent);

    // calculates the power
    result = pow(base,exponent);

    printf("%.1lf^%.1lf = %.2lf", base, exponent, result);

    return 0;
} 

Output

Enter a base number: 2.3
Enter an exponent: 4.5
2.3^4.5 = 42.44