Number Base Converter
How to Convert Decimal to Binary
Computers count in binary (base 2) while we count in decimal (base 10). Enter a number below to convert it between decimal, binary, hexadecimal and octal at once.
Convert between number bases
Octal (8)
12
Decimal (10)
10
Hex (16)
a
Steps to convert decimal to binary
- Type your decimal number into the tool above.
- Read the binary, hex and octal equivalents instantly.
- Switch the input base to convert the other way too.
How decimal to binary works
To convert by hand, divide the number by 2 repeatedly and read the remainders bottom to top. For example 13 → 1101. The converter handles this for any number and shows the result in several bases at once.
Frequently asked questions
What is binary used for?
Binary is the native language of computers — every value is ultimately stored as 1s and 0s. Programmers also use hex as a shorter way to read binary.
Can it convert hex or octal too?
Yes. The tool converts between decimal, binary, hexadecimal and octal in any direction.