Simple Binary to Decimal converter

This is a very simple program written in C to convert 16bit binary numbers to decimal numbers.

#include <stdio.h>

int main(int argc, char *argv[]){
    char c;
    int i,dec_val;
   
    printf(" Give a binary number with length 16 : \n");
    i=15;
    dec_val=0;
    while (i>=0) {
        dec_val+= (getchar()-'0')*(1 << i);
        i=i-1;
    }
    printf ("%d \n",dec_val);
    return(0);
}

As you probably noticed no check is made. User inputs 16 chars which must be 0 and 1. After that characters are read and expected to be 0-1 and multiplied by a power of two.
Also this post here is a decimal to binary converter.