C program to convert form binary number into decimal

/* Write a C program to convert the given binary number into decimal */

#include <stdio.h>

void main()
{
  int   num, bnum, dec = 0, base = 1, rem ;

  printf("Enter a binary number(1s and 0s)\n");
  scanf("%d", &num);           /*maximum five digits */

  bnum = num;

  while( num > 0)
  {
rem = num % 10;
dec = dec + rem * base;
num = num / 10 ;
base = base * 2;
  }

  printf("The Binary number is = %d\n", bnum);
  printf("Its decimal equivalent is =%d\n", dec);

} /* End of main() */

/*---------------------------------------------
Output
Enter a binary number(1s and 0s)
10101
The Binary number is = 10101
Its decimal equivalent is =21
----------------------------------------------*/