📐 Number Base Converter

Convert numbers between different bases: binary (2), octal (8), decimal (10) and hexadecimal (16). Select the input base and see all conversions simultaneously.

Input base

Conversion

Binary (2)
11111111
Octal (8)
377
Decimal (10)(input)
255
Hexadecimal (16)
FF
Binary (grouped)1111 1111

The number base converter changes a value between binary, octal, decimal and hexadecimal and shows every representation at a glance. It is handy for programmers, students and anyone working across different number bases.

How the calculator works and what it’s for

What number bases mean

The everyday decimal system uses ten digits (0–9). Binary uses just two (0 and 1), octal uses eight and hexadecimal uses sixteen, where the letters A–F stand for the values 10 to 15.

Computers process data as binary at the lowest level, but hexadecimal is a more compact way for people to read the same bits.

How the conversion works

The converter first reads the input from its own base into decimal and then displays it in the other bases. Each digit is weighted by powers of its base.

Binary output is often grouped into blocks of four bits, which is easier to read and maps directly to a single hexadecimal digit.

Who it is for

It is an everyday helper in programming, electronics and networking, where addresses and colors are frequently written in hexadecimal.

For students it illustrates how the same number looks different in different bases without being a different value.

Good to know

Hexadecimal numbers are often marked with the prefix 0x and binary with 0b to avoid confusing the base.

The same string of bits can always be read as both binary and hexadecimal — it is only the notation that changes, not the value.

🔄 Reviewed June 2026

Frequently asked questions

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