Binary to Decimal Converter

Binary to decimal — instant base-10 conversion

This tool converts a binary number (base 2) into its decimal (base 10) value, and also shows the hexadecimal and octal equivalents. It is built for students learning number systems, programmers reading register values or bit masks, and anyone decoding data stored in binary. Spaces between groups are ignored, so grouped input like 1010 1101 works exactly the same as 10101101.

How it works

Each binary digit stands for a power of two, increasing from right to left: 1, 2, 4, 8, 16, and so on. The decimal value is the sum of the powers wherever the digit is 1. The tool strips whitespace, checks the input contains only 0 and 1, then parses it as base 2 and re-renders the same value in base 10, base 16 (hex) and base 8 (octal).

Example

Take 10101101:

128 + 0 + 32 + 0 + 8 + 4 + 0 + 1 = 173

So 10101101 = 173 decimal, AD in hex and 255 in octal, across 8 bits.

Everything runs in your browser — nothing is uploaded.