Number Base Converter
Convert between decimal, binary, octal, and hexadecimal
What it does: Convert between decimal, binary, octal, and hexadecimal. This free online tool works entirely in your browser with no installation required.
How to use:
- Enter a value into the decimal, binary, octal, or hexadecimal input field.
- The other three fields update automatically to show equivalent values in every base.
- Select and copy any converted value for use in your code or documentation.
Privacy: All processing happens in your browser. No data sent to servers.
Best for: Anyone who needs quick Number Base Converter without installing software.
Number Bases Explained
Number bases are systems for representing numbers using a specific set of digits. While we use decimal (base 10) in everyday life, computers use binary (base 2) internally, and programmers frequently work with hexadecimal (base 16) and octal (base 8) for convenience. Understanding how to convert between these bases is essential for programming and computer science.
Common Number Bases
- Decimal (Base 10) — Uses digits 0-9. This is the standard system for human counting and mathematics, likely because we have ten fingers.
- Binary (Base 2) — Uses digits 0 and 1. Computers represent all data as binary values (bits). A group of 8 bits is a byte. For example, the decimal number 255 is written as
11111111in binary. - Octal (Base 8) — Uses digits 0-7. Octal was more common in early computing and is still used for Unix file permissions (e.g.,
755forrwxr-xr-x). - Hexadecimal (Base 16) — Uses digits 0-9 and letters A-F (representing values 10-15). Hex is widely used for memory addresses, color codes (
#FF0000), and representing binary data compactly. One hex digit represents exactly 4 bits.
Practical Applications
- Memory debugging — Memory addresses and dumps are displayed in hexadecimal because it is more compact and readable than binary.
- Color values — Web colors use hexadecimal (e.g.,
#4361EE) where each pair of digits represents the red, green, and blue components. - Bitwise operations — Low-level programming uses binary representations for flags, permissions, and efficient calculations.
- File permissions — Unix/Linux file permissions are expressed in octal, where each digit represents read (4), write (2), and execute (1) permissions.
- Cryptography — Hash values, encryption keys, and certificates are commonly displayed in hexadecimal for readability.