DevToolbox

Decimal to Binary Converter

This tool converts an ordinary decimal number into its binary (base-2) representation, the number system used internally by computer hardware and software.

Your data stays in your browser — this tool runs entirely on the client side and nothing is uploaded to a server.

How to Use the Decimal to Binary Converter

  1. Type a decimal (base-10) number into the input box.
  2. The binary equivalent appears instantly.
  3. Use the linked base converter to also view hexadecimal and octal forms.

How the conversion works

Converting decimal to binary repeatedly divides the number by 2, recording the remainder at each step. Reading those remainders from last to first gives the binary representation. For example, 11 divided by 2 repeatedly gives remainders 1, 1, 0, 1 (reading bottom-up), producing the binary value 1011.

Practical uses

Converting to binary is useful for understanding how numbers are stored at a low level, working with bitwise operations and flags, configuring networking values like subnet masks, and general computer science education.

Example

Convert 11
11
1011

Tips

  • Every additional bit in a binary number doubles the largest decimal value it can represent.
  • An 8-bit binary number (a byte) can represent decimal values 0 through 255.

Frequently Asked Questions

How many bits do I need to represent a given decimal number?

You need enough bits so that 2^bits is greater than the number. For example, representing up to 255 requires 8 bits (2^8 = 256).

Related Tools

Binary to Decimal Converter Convert binary numbers to decimal (base-10). Binary to Hex Converter Convert binary numbers to hexadecimal. Hex to Binary Converter Convert hexadecimal numbers to binary.