Number Base Converter

Convert numbers between binary, octal, decimal, hex and any base.

Decimal value

255

255 in base 10

Binary

11111111

Octal

377

Hexadecimal

Bit length

8 bits

Bytes needed

Base 36

Each digit is multiplied by the base raised to its position, then the total is re-expressed in the target base.

Conversion uses BigInt arithmetic, so numbers with hundreds of digits convert exactly.
One hexadecimal digit is exactly four bits, which is why a byte is always two hex digits.

Base	Value
Base 2 (binary)	11111111
Base 8 (octal)	377
Base 10 (decimal)	255
Base 16 (hex)	ff
Base 32	7v
Base 36	73

What does Number Base Converter do?

Convert integers between any bases from 2 to 36 with exact arithmetic, so very large values never lose precision. Binary, octal, decimal and hexadecimal are shown together, and any custom base is a field away.

How to Use Number Base Converter

1
Enter a numberIn whichever base you have.
2
Select that baseOr use one of the labelled fields.
3
Read every other baseThey all update together.

Key Features

Binary, octal, decimal and hexadecimal shown simultaneously
Any custom base from 2 to 36
BigInt arithmetic, so hundred-digit numbers convert exactly
Optional digit grouping for readability
Bit length and byte size reported for the value

Frequently Asked Questions

How do I convert binary to decimal?

Multiply each digit by 2 raised to its position from the right and add them up. 1011 is 8 + 0 + 2 + 1 = 11.

Why is hexadecimal used so much in computing?

Because one hex digit is exactly four bits, so a byte is always two hex digits. That makes hex a compact, exact shorthand for binary — which decimal never is.

What is base 36?

Digits 0–9 followed by letters a–z, giving the most compact representation using only alphanumeric characters. It is used for short IDs and URL slugs.

Can it convert negative numbers?

Yes, using a minus sign. Two’s complement representation is a different concept — it depends on a fixed bit width, which this converter does not assume.