C Program to Calculate Value of PI using Leibniz Formula

The Leibniz formula is an infinite series method of calculating Pi. The formula is a very simple way of calculating Pi, however, it takes a large amount of iterations to produce a low precision value of Pi.

In this program we first read number of term to consider in series from user and then apply Leibniz formula to caluclate value of Pi.

This C program calculates value of Pi using Leibniz formula.

C Source Code: Calculation of Pi using Leibniz Formula


int main()
 long int i, n;
 double sum=0.0, term, pi;
 printf("Enter number of terms: ");
 scanf("%ld", &n);

 /* Applying Leibniz Formula */
 for(i=0;i< n;i++)
  term = pow(-1, i) / (2*i+1);
  sum += term;
 pi = 4 * sum;

 printf("\nPI = %.6lf", pi);
 return 0;


Enter number of terms: 1000000

PI = 3.141592
To get more accurate result use higher value of n.