How do I convert binary to decimal?

Multiply each binary digit by its power of two and add them up: 1011₂ = 1×8 + 0×4 + 1×2 + 1×1 = 11. Or just paste the binary number into this tool.

Why is hexadecimal used in programming?

One hex digit represents exactly four binary bits, so a byte is always two hex digits (e.g. 255 = 0xFF). That makes hex a compact, human-readable way to write binary data, memory addresses, and colors.

Can this handle numbers larger than 64 bits?

Yes. The converter uses arbitrary-precision integers, so there is no practical size limit.

Number Base Converter

Convert integers between binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), or any base from 2 to 36. Enter a number in any base and see it in all the others instantly. The converter uses arbitrary-precision arithmetic, so even very large numbers convert without losing accuracy.

Converters

Number

Input base

Binary (base 2): 11111111
Octal (base 8): 377
Decimal (base 10): 255
Hexadecimal (base 16): ff

Private by default

This tool runs entirely in your browser. Your data is never uploaded to a server.

How to use

3 clear steps.

Choose the base of your input number (binary, octal, decimal, or hex).
Type the number — digits are validated for the chosen base.
Read the converted value in every other base, and copy any of them.

Good to know

Frequently asked questions

How do I convert binary to decimal?: Multiply each binary digit by its power of two and add them up: 1011₂ = 1×8 + 0×4 + 1×2 + 1×1 = 11. Or just paste the binary number into this tool.
Why is hexadecimal used in programming?: One hex digit represents exactly four binary bits, so a byte is always two hex digits (e.g. 255 = 0xFF). That makes hex a compact, human-readable way to write binary data, memory addresses, and colors.
Can this handle numbers larger than 64 bits?: Yes. The converter uses arbitrary-precision integers, so there is no practical size limit.