Decimal to binary — base-10 to base-2
Enter a whole number and this tool returns its binary (base 2) representation, neatly grouped into 4-bit nibbles, plus the hexadecimal and octal forms. It is handy for programmers, students learning number systems, and anyone working with bitmasks or low-level data.
How it works
Binary is a base-2 system: each digit (bit) represents a power of two, doubling from right to left — 1, 2, 4, 8, 16, and so on. To convert a decimal number you repeatedly divide by two and record the remainders; reading those remainders bottom to top gives the binary value. The tool then pads the result to a multiple of four bits and groups it into nibbles for readability, and also derives the hex and octal forms. Inputs must be whole, non-negative integers up to 9,007,199,254,740,991.
Example
Convert 173:
173 = 128 + 32 + 8 + 4 + 1 = 10101101 (grouped: 1010 1101)
| Base | Value |
|---|---|
| Decimal (10) | 173 |
| Binary (2) | 1010 1101 |
| Hex (16) | AD |
| Octal (8) | 255 |
The whole conversion runs in your browser — nothing is uploaded.