🔣 Number System Converter

Convert numbers between decimal, binary, hexadecimal and octal instantly.

Number

From base

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Quick reference

Decimal	Binary	Hex	Octal
0	0	0	0
10	1010	A	12
16	10000	10	20
255	11111111	FF	377
1024	10000000000	400	2000

Frequently asked questions

What is binary?

Binary is a base-2 number system that uses only 0 and 1. It is the fundamental language of all digital computers and electronic devices.

What is hexadecimal used for?

Hexadecimal (hex) is used in programming to represent memory addresses, colours in web design (e.g. #FF5733) and byte values in a compact form. Each hex digit represents exactly 4 binary digits.

What is 255 in binary?

255 in binary is 11111111 — eight 1s. In hexadecimal it is FF. This is why the maximum value of a single byte is 255.