Decimal to Binary

Decimal to Binary

Use our tool to change a regular number to a binary number. It will show you the steps and rules used to make this conversion.

The decimal and binary number systems are fundamental concepts in computer science and mathematics. Converting decimal numbers to binary is a crucial skill, especially for those working in fields related to computing and digital systems. This article will guide you through the process of converting decimal to binary, explain the importance of binary numbers, and provide practical examples to solidify your understanding.

Understanding Number Systems

Before diving into the conversion process, it’s essential to understand what decimal and binary number systems are.

The Decimal Number System

The decimal number system, also known as the base-10 system, is the most commonly used number system in everyday life. It consists of ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. The value of a number in the decimal system is determined by its digits and their positions. Each position represents a power of 10, increasing from right to left.

The Binary Number System

The binary number system, or base-2 system, is used extensively in computing and digital electronics. It consists of only two digits: 0 and 1. Each digit in a binary number is called a bit. Similar to the decimal system, the value of a binary number is determined by its digits and their positions, but each position represents a power of 2.

Why Convert Decimal to Binary?

Converting decimal numbers to binary is essential in various fields, particularly in computer science and digital electronics. Computers operate using binary logic, so understanding binary numbers and their operations is crucial for programming, network communication, and designing digital circuits.

Conversion Methods

There are several methods to convert decimal numbers to binary. We will explore two common methods: the division-remainder method and the subtraction method.

Division-Remainder Method

The division-remainder method is a straightforward technique for converting a decimal number to binary. Follow these steps:

  1. Divide the Decimal Number by 2: Start with the decimal number you want to convert.
  2. Record the Remainder: Write down the remainder (0 or 1) after dividing by 2.
  3. Update the Quotient: Update the decimal number to the quotient obtained from the division.
  4. Repeat: Repeat the process with the updated quotient until it becomes 0.
  5. Reverse the Remainders: The binary representation is obtained by reading the remainders in reverse order.

Example: Convert 23 to Binary

  1. 23 ÷ 2 = 11 (remainder 1)
  2. 11 ÷ 2 = 5 (remainder 1)
  3. 5 ÷ 2 = 2 (remainder 1)
  4. 2 ÷ 2 = 1 (remainder 0)
  5. 1 ÷ 2 = 0 (remainder 1)

Reading the remainders in reverse order, we get 23 in binary as 10111.

Subtraction Method

The subtraction method involves subtracting the largest possible power of 2 from the decimal number until you reach zero. The steps are as follows:

  1. Identify the Largest Power of 2: Find the largest power of 2 less than or equal to the decimal number.
  2. Subtract: Subtract this value from the decimal number.
  3. Record the Binary Digit: Write a 1 in the binary place value corresponding to the power of 2 used.
  4. Repeat: Repeat the process with the new value obtained from the subtraction until it becomes 0.

Example: Convert 23 to Binary

  1. The largest power of 2 ≤ 23 is 16 (2^4).
  2. 23 - 16 = 7. Record a 1 in the 2^4 place.
  3. The largest power of 2 ≤ 7 is 4 (2^2).
  4. 7 - 4 = 3. Record a 1 in the 2^2 place.
  5. The largest power of 2 ≤ 3 is 2 (2^1).
  6. 3 - 2 = 1. Record a 1 in the 2^1 place.
  7. The largest power of 2 ≤ 1 is 1 (2^0).
  8. 1 - 1 = 0. Record a 1 in the 2^0 place.

The binary representation is obtained by placing 0s in all other places. Thus, 23 in binary is 10111.

Binary Conversion in Programming

In programming, converting decimal to binary is often required for various applications, such as data encoding, cryptography, and algorithm design. Most programming languages provide built-in functions to facilitate this conversion.

Python Example

Here’s how you can convert a decimal number to binary in Python: 

decimal_number = 23
binary_number = bin(decimal_number)

The output will be:


JavaScript Example

In JavaScript, you can use the toString() method:


let decimalNumber = 23;
let binaryNumber = decimalNumber.toString(2);

The output will be:


Practical Applications of Binary Numbers

Binary numbers are foundational in digital systems. Here are some practical applications:

Computer Architecture

Binary numbers are used in computer architecture to design and implement processors, memory, and other digital components. Each instruction and piece of data is represented in binary.


In networking, binary numbers are used to represent IP addresses and subnet masks. For instance, an IPv4 address like is represented in binary as 11000000.10101000.00000000.00000001.

Data Encoding

Binary encoding is used to store and transmit data efficiently. File formats, such as images, videos, and text files, are encoded in binary.

Logic Gates and Circuits

Logic gates, the building blocks of digital circuits, operate on binary numbers. Boolean algebra, which underlies logic gates, uses binary values to perform logical operations.

Common Pitfalls and Tips

Accuracy in Manual Conversion

When converting manually, ensure you correctly identify and handle powers of 2. Small errors can lead to incorrect results. Double-check each step to avoid mistakes.

Understanding Binary Arithmetic

Familiarize yourself with binary arithmetic, including addition, subtraction, multiplication, and division. These operations are essential for various computing tasks and can help you better understand binary numbers.

Use of Tools

Don’t hesitate to use online tools and calculators for conversion, especially when dealing with large numbers. They can save time and reduce errors.


Understanding how to convert decimal numbers to binary is a fundamental skill in computer science and digital electronics. Whether you use the division-remainder method, the subtraction method, or built-in programming functions, mastering this process is essential for various applications. Binary numbers are integral to computer architecture, networking, data encoding, and digital circuits, making this knowledge indispensable in the modern technological landscape.

By following the steps outlined in this article and practicing with different examples, you can enhance your proficiency in converting decimal numbers to binary, paving the way for a deeper understanding of digital systems.


Azahar Ahmed

CEO / Co-Founder

I am Azahar Ahmed, a youthful Engineer, Entrepreneur, Digital Marketer, and Motivational speaker native to Nagaon, Assam, India. Originating from a middle-class background, I am the sole son. My accomplishments are indebted to my father, a Teacher, and my mother, formerly a Teacher but now devoted to our well-being. My mother has been my closest ally, and unitedly, my parents have fostered and realized all my aspirations, epitomizing the perfect parents.

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