In this tutorial, you will learn how to write a C++ Program to convert a given decimal number to binary using bitset library.

C++ Convert Decimal to Binary

To convert decimal number to binary, use std::bitset. bitset stores bits, and we can convert this into a string.

We need to set the number of bits while using bitset as shown in the following.



In the following program, we read a number into n (decimal value), and find its binary (16 bits length) using std::bitset.


#include <iostream>
#include <bitset>
using namespace std;

int main() {
    int n;
    cout << "Enter a decimal number  : ";
    cin >> n;
    string binary = bitset<16>(n).to_string();
    cout << "Binary : " << binary << endl;


Enter a decimal number  : 45
Binary : 0000000000101101
Program ended with exit code: 0
Enter a decimal number  : 7
Binary : 0000000000000111
Program ended with exit code: 0


In this C++ Tutorial, we learned how to convert decimal to binary in C++ using std::bitset.