Convert Binary to Decimal in C#

Firstly, set the binary value −

int num = 101;

Now assign the binary to a new variable −

binVal = num;

Till the value is greater than 0, loop through the binary number and base value like this,

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

Example

The following is the code to convert binary to decimal.

Live Demo

using System;
using System.Collections.Generic;
using System.Text;
namespace Demo {
   class MyApplication {
      static void Main(string[] args) {
         int num, binVal, decVal = 0, baseVal = 1, rem;
         num = 101;
         binVal = num;
         while (num > 0) {
            rem = num % 10;
            decVal = decVal + rem * baseVal;
            num = num / 10 ;
            baseVal = baseVal * 2;
         }
         Console.Write("Binary Number: "+binVal);
         Console.Write("
Decimal: "+decVal);
         Console.ReadLine();
      }
   }
}

Output

Binary Number: 101
Decimal: 5