# C program to Calculate Factorial of a Number Using Recursion

To understand this example, you should have knowledge of following C programming topics:

This program takes a positive integer from user and calculates the factorial of that number. Instead of loops to calculate factorial, this program uses recursive function to calculate the factorial of a number.

## Source Code to Calculate Factorial Using Recursion

```
/* Source code to find factorial of a number. */
#include<stdio.h>
int factorial(int n);
int main()
{
int n;
printf("Enter an positive integer: ");
scanf("%d",&n);
printf("Factorial of %d = %ld", n, factorial(n));
return 0;
}
int factorial(int n)
{
if(n!=1)
return n*factorial(n-1);
}
```

**Output**

Enter an positive integer: 6 Factorial of 6 = 720