~/devtools / number
tool::number

Number Base
Converter

Convert between binary, octal, decimal, and hexadecimal in real time. Edit any field and the rest update automatically.

ad · 728×90
ad · 300×250
// about this tool

About Number Base Converter

A number base (or radix) defines how many unique digits, including zero, a positional numeral system uses. While we use base-10 (decimal) in everyday life, computer science relies heavily on base-2 (binary), base-8 (octal), and base-16 (hexadecimal) for representing data at the hardware level.

Binary (base 2) uses only 0 and 1, making it the native language of digital circuits. Octal (base 8) uses digits 0–7 and is commonly seen in Unix file permissions (chmod). Hexadecimal (base 16) uses digits 0–9 and letters A–F, and is ubiquitous in memory addresses, color codes, and cryptographic hashes.

This tool converts all four bases simultaneously. Edit any field — binary, octal, decimal, or hex — and the other three update instantly. It's designed for developers who frequently need to cross-reference values across different bases during debugging, embedded programming, or web design.

Common Use Cases
  • ▸Calculating Linux chmod permissions (e.g. 755 = 111 101 101 in binary)
  • ▸Converting HTML/CSS hex color codes to decimal RGB values
  • ▸Inspecting memory addresses or pointer values in different bases
  • ▸Learning binary arithmetic and bit patterns
  • ▸Verifying register values in assembly or embedded development
Frequently Asked Questions
Q. What do A, B, C mean in hexadecimal?
A=10, B=11, C=12, D=13, E=14, F=15. Hex uses letters A–F to represent values 10–15 in a single digit, allowing 0–255 to be expressed in just two characters.
Q. Can I convert negative numbers or decimals?
This tool supports non-negative integers only. Negative numbers require two's complement representation, and fractional values use a different notation per base, which are not covered here.
Q. Can I input values with 0x or 0b prefixes?
Enter raw digits only — no prefixes. For hex, include letters A–F directly. For binary, use only 0 and 1.