Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal. See all bases at once. Free online base converter.

Last updated: June 1, 2026

From Base

→

To Base

Input Number

Result

What is Number Base Converter?

A number base converter translates numbers between different numeral systems — decimal (base-10), binary (base-2), octal (base-8), and hexadecimal (base-16). Computers operate in binary, memory addresses use hexadecimal, some Unix permissions use octal, and humans think in decimal. Developers constantly need to translate between these systems when debugging, reading memory dumps, setting file permissions, working with color codes, understanding network masks, or reading low-level system output.

How It Works

Enter a number in any base and the tool displays its equivalent in all supported bases simultaneously. For conversion, it first parses the input in its source base to determine the numeric value, then formats that value in each target base using the appropriate digit set. Binary uses 0-1, octal uses 0-7, decimal uses 0-9, and hexadecimal uses 0-9 plus A-F. The tool handles arbitrarily large numbers and shows the conversion steps for educational purposes.

Quick Reference

Decimal	Binary	Octal	Hexadecimal
0	0000	0	0
8	1000	10	8
10	1010	12	A
15	1111	17	F
16	10000	20	10
255	11111111	377	FF

Common Use Cases

•Converting hex color codes to binary for understanding bit-level color representation
•Reading binary data dumps and converting to hexadecimal for more compact display
•Setting Unix file permissions (chmod) by converting between octal and binary representations
•Understanding subnet masks and IP addressing by converting between decimal and binary
•Debugging memory addresses and pointers displayed in hexadecimal by converting to decimal
•Converting between number formats when working with hardware registers and bit flags