Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly.
Overview
Convert integers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). These conversions are routine in computer science, electronics, and low-level programming. The tool shows all four representations simultaneously so you can cross-reference without running multiple conversions.
Common use cases
- Convert decimal values to hexadecimal for colour code or memory address work.
- Translate binary data for bitwise operation analysis.
- Understand octal Unix file permission values (e.g. chmod 755).
- Cross-verify register values across base representations in embedded development.
Examples and notes
- Decimal 255 = 0xFF in hex = 11111111 in binary = 377 in octal.
- Unix permission 755 in octal = 111 101 101 in binary = rwxr-xr-x.
- Web colour #1A2B3C has red=26, green=43, blue=60 in decimal.
Important note
This tool handles non-negative integers only. Negative numbers, floating-point values, and two's complement representations are not supported. For signed binary arithmetic, use a dedicated programmer calculator.
Frequently Asked Questions
What is binary and why do computers use it?
Binary is base-2, using only digits 0 and 1. Computers use binary because transistors have two stable states — on and off — which map naturally to 1 and 0.
What is hexadecimal used for?
Hexadecimal (base-16) is used in programming for memory addresses, colour codes (#FF5733), byte values, and encoding because it compactly represents 4 binary bits per digit.
What is octal and where is it still used?
Octal (base-8) is used in Unix/Linux file permissions. For example, chmod 755 means rwxr-xr-x in binary — 111 101 101.
What is the decimal equivalent of 0xFF?
0xFF in hexadecimal = 255 in decimal = 11111111 in binary. It represents the maximum value of a single byte.