Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal in one place.
Programmers constantly move numbers between bases — binary for bits, hexadecimal for colours and memory, decimal for humans, octal for permissions. Number Base Converter translates a value between binary, octal, decimal and hexadecimal in one place.
How to use number base converter
- 1. Enter a number and its base.
- 2. See it in binary, octal, decimal and hexadecimal.
- 3. Copy the representation you need.
When to use Number Base Converter
Read a hex or binary value
Convert a hex colour or binary flag into decimal to understand it.
Work with permissions
Move between octal and other bases when dealing with file permissions.
Learning and debugging
See a number across bases while studying or troubleshooting.
What you can type
Choose the base of your input, then type the number. Prefixes matching that base are accepted (0x for hex, 0b for binary, 0o for octal), as are spaces or underscores between digits (1111_0000) and a minus sign. Numbers of any size convert exactly — there's no rounding past 2^53, the point where many converters start losing digits. Whole numbers only; fractions aren't supported. Hex output is in capitals.
Two everyday examples
File permissions: chmod 755 is octal, and each digit is three bits of read-write-execute — 7 is 111 (rwx), 5 is 101 (r-x). Colours: the CSS colour #F27200 is three hex bytes; F2 in decimal is 242, 72 is 114, 00 is 0 — the same as rgb(242, 114, 0).
Frequently asked questions
Which bases are supported?
Binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16).
Can I convert from any base to any base?
Yes — enter your number in its base and read it in all the others.
Is my input uploaded?
No — conversion runs in your browser.