Number System Converter


Number systems are the foundation of mathematics and computing. They provide a structured way to represent and manipulate quantities. Each number system uses a set of symbols and rules to express numerical values. Understanding these systems is essential for various purposes, from programming to data storage. Explore our Number System Converter tool.

What are Number Systems?

A number system is a way of expressing numbers using a specific set of symbols or digits. The choice of symbols and rules for combining them varies between different number systems. The most common number systems are Binary, Decimal, Hexadecimal, and Octal.

Why are Number Systems Important?

Number systems are crucial because they allow us to represent and work with numbers in different contexts. For example, computers use the binary system to process data, while decimal is the standard for everyday mathematics. Hexadecimal and octal systems find applications in programming and data storage.

Binary Number System

The binary number system uses two digits, 0 and 1. These digits are also known as bits. Computers use binary because electronic circuits can easily represent two states, corresponding to 0 and 1.

Understanding Binary Digits (Bits)

In binary, each digit represents a power of 2. The rightmost digit is 2^0, the next is 2^1, then 2^2, and so on. To convert a binary number to decimal, you add up the values of the bits with a 1.


  • Binary: 1101
  • Decimal: 12^3 + 12^2 + 02^1 + 12^0 = 8 + 4 + 0 + 1 = 13

Converting Binary to Decimal

Converting binary to decimal involves multiplying each bit by the appropriate power of 2 and adding up the results, as shown in the example above.

Binary to Hexadecimal and Octal

Binary can be converted to hexadecimal by grouping bits into sets of four and converting each set to its hexadecimal equivalent. Octal uses groups of three bits.

Decimal Number System

The decimal number system is the one we use most often in our daily lives. It uses ten digits, from 0 to 9.

Decimal Digits and Place Value

In decimal, each digit represents a power of 10. The rightmost digit is 10^0, the next is 10^1, then 10^2, and so on.

Converting Decimal to Binary, Hexadecimal, and Octal

Converting decimals to other number systems involves dividing the decimal number by the base of the target system (2 for binary, 16 for hexadecimal, and 8 for octal) and recording the remainder.

Hexadecimal Number System

Hexadecimal uses 16 symbols: 0-9 for values 0 to 9 and A-F for values 10 to 15.

Digits and Representation

Hexadecimal simplifies binary representation, as each hexadecimal digit corresponds to four binary digits (bits).

Converting Hexadecimal to Binary, Decimal, and Octal

To convert hexadecimal to binary, split each hexadecimal digit into its binary equivalent. For decimal conversion, convert hexadecimal to binary first and then to decimal using the earlier methods.

Octal Number System

Octal uses eight digits: 0-7.

Digits and Usage

Octal numbers are less common in everyday life but find applications in computer programming, particularly in UNIX file permissions.

Converting Octal to Binary, Decimal, and Hexadecimal

Converting octal to binary or decimal is similar to converting hexadecimal but with groups of three bits.

Practical Applications

Number systems have practical uses in various fields:

Where are Different Number Systems Used?

  • Binary: Computer architecture, digital circuits, and machine-level programming.
  • Decimal: Everyday mathematics and financial calculations.
  • Hexadecimal: Programming (memory addresses, color codes) and low-level debugging.
  • Octal: UNIX file permissions and legacy systems.

Real-world Examples

  • Converting file sizes (bytes) from binary to decimal for storage.
  • Using hexadecimal for web color codes (#RRGGBB).
  • Managing file permissions in UNIX systems using octal notation.

Understanding number systems, whether binary, decimal, hexadecimal, or octal, is essential in the digital age. These systems underpin our technological world, from computer programming to everyday calculations. Try our number system converter tool.


What is the binary representation of the number 42?

The binary representation of 42 is 101010.

How do I convert a hexadecimal number to an octal?

To convert a hexadecimal number to octal, first convert it to binary and then to octal using groups of three bits.

Are there any historical uses of octal numbers?

Octal numbers were historically used in early computers and programming, but their use has diminished with the widespread adoption of hexadecimal and binary.

Can I use number systems in everyday life?

While you may not use them explicitly, number systems play a significant role in various technological aspects of everyday life, such as computing, programming, and data storage.

Where can I find more practice problems for number system conversion?

Many online resources and textbooks offer practice problems for number system conversions. You can also join online forums or communities focused on mathematics and computer science for additional support and exercises.