How do I convert binary to decimal?

Type your binary digits into the Base 2 row and the Base 10 row updates instantly. For example 11111111 in binary becomes 255 in decimal. The converter also shows the same value in octal, hex and any other base you have enabled.

What is the largest number this base converter supports?

There is no practical limit. The tool uses JavaScript BigInt internally, so it converts arbitrarily large integers exactly — you can paste a 200-digit number and every base stays precise, with no rounding or overflow.

Which bases can I convert between?

Any whole-number base from 2 to 36. That covers binary (2), octal (8), decimal (10), duodecimal (12), hexadecimal (16), Base32 and Base36. Digits 0-9 are used first, then letters A-Z represent values 10 through 35.

Does it handle the 0x, 0b and 0o prefixes?

Yes. If you paste a literal like 0xFF into the hex row, 0b1010 into the binary row or 0o17 into the octal row, the matching prefix is stripped automatically so the value parses correctly.

Why are letters used in higher bases?

Once a base goes above 10 it needs symbols for values larger than 9. The standard convention extends the digits with letters: A is 10, B is 11, and so on up to Z which is 35 in base 36. That is why a hex value like FF means 255.

Completely. Every conversion happens locally in your browser using built-in math — no number you enter is ever sent to a server, and your saved history lives only in your own browser storage.

Number Base Converter

A number base converter that translates a whole number between binary, octal, decimal, hexadecimal and any arbitrary base from 2 to 36 — all at once, with live cross-fill. Edit any row and every other base recalculates instantly, so you never copy-paste between separate tools. It is built for programmers reading memory dumps, students learning positional notation, embedded engineers juggling register values, and anyone who has ever needed to know what 0xDEADBEEF looks like in decimal or binary.

How it works

A number’s value is independent of how you write it down — only the base (or radix) changes the symbols. In base 10 the string 255 means 2 hundreds, 5 tens and 5 ones. In base 16 the same quantity is FF, and in base 2 it is 11111111. This converter keeps a single canonical value in memory and re-renders it in every base you have switched on.

When you type into a field, the tool parses your digits in that field’s base, builds an exact integer, then formats that integer back out into all the other bases. Because it uses JavaScript BigInt for the arithmetic, the conversion is exact for numbers of any size — there is no 53-bit floating-point ceiling and no silent overflow, so a hundred-digit input round-trips perfectly. Bases above 10 use letters after the digits: A is 10, B is 11, up to Z which is 35, giving the full 2-to-36 range.

Beyond the basics, the panel shows useful insight stats for the current value: its bit length, byte count, the number of set bits (population count) and whether it is odd or even. You can toggle digit grouping (bytes for binary, nibbles for hex, thousands for decimal), switch hex letters to uppercase, and save values to a history you can restore with one click. Pasted literals such as 0xFF, 0b1010 or 0o17 have their prefixes stripped automatically.

Example

Say a debugger shows you the address 0x1F4. Type 1F4 into the Base 16 row and the converter immediately fills in the rest:

Base	Value
2 (binary)	1 1111 0100
8 (octal)	764
10 (decimal)	500
16 (hex)	1F4
36	DW

The insight panel reports 9 bits, 2 bytes and 6 set bits. Add a custom base — say 3 — and you will see 500 written as 200120. Every figure is computed in your browser; nothing is uploaded.

Why convert bases at all

Hexadecimal is compact and maps cleanly onto bytes, which is why colours, memory addresses and hashes use it. Binary mirrors the hardware’s actual on/off state, so it is indispensable for bit-masks and flags. Octal still appears in Unix file permissions. Switching fluently between them — and the occasional exotic base for puzzles, encodings or teaching — is a routine task this tool makes friction-free.