How does decimal to binary conversion work?
Divide the decimal number by 2 repeatedly. The sequence of remainders (read in reverse) gives the binary representation. Example: 13 → 1101 in binary.
Decimal to Binary Converter instantly transforms base-10 integers into their binary (base-2) equivalents. Understanding and working with binary is fundamental in computer science, embedded programming, network engineering, and digital electronics. Use this tool to convert register values, build bitmasks, learn binary arithmetic, or verify binary conversions in your program code.
Decimal to binary conversion uses the divide-by-2 (repeated division) method: repeatedly divide the decimal number by 2 and record the remainder (0 or 1) each time. Reading remainders from bottom to top gives the binary representation. Example: 10 ÷ 2 = 5 R0, 5 ÷ 2 = 2 R1, 2 ÷ 2 = 1 R0, 1 ÷ 2 = 0 R1 → binary = 1010.
Divide the decimal number by 2 repeatedly. The sequence of remainders (read in reverse) gives the binary representation. Example: 13 → 1101 in binary.
A bitmask is a binary number used in bitwise operations to select, set, or clear specific bits. Convert your decimal flag value to binary to see and verify which bits it sets.
The number of binary digits (bits) needed is ⌈log₂(n+1)⌉. For example: 255 needs 8 bits (11111111), 65535 needs 16 bits.
In this tool, unsigned integers are supported. For signed negative numbers in two's complement, invert the bits and add 1 to the positive representation.
No. Conversion runs entirely in your browser.
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Tool workspace
Free decimal to binary converter online — instantly convert any decimal (base-10) number to binary (base-2). Shows step-by-step working. Supports integers up to 64-bit. No login.
Input
Output
Input
202
Output
11001010