Binary / Number Base Converter
Type in any field — binary, octal, decimal, or hex — and all others update instantly.
Convert a number from any base (2–36) to any other base.
How to use
- Type any number in the Binary, Octal, Decimal, or Hex field — all four update simultaneously
- The bit visualization shows the binary representation grouped in nibbles (4 bits each)
- Bit info shows how many bits are needed, and the signed/unsigned range for that bit width
- If the decimal value is 32–126, the ASCII character is shown below the visualization
- The Custom Base Converter supports any base from 2 to 36 (uses 0–9 and A–Z)
- Hex input is case-insensitive
About this Binary/Decimal/Hex/Octal Converter
Computers store all data in binary (base 2), but binary is unwieldy for humans to read and write directly, which is why programmers commonly translate between binary and more compact representations like decimal, hexadecimal, and octal.
The four number bases compared
- Binary (base 2): only digits 0 and 1; how computers store data at the hardware level
- Octal (base 8): digits 0–7; historically used in older computing systems and still seen in Unix file permission codes (like chmod 755)
- Decimal (base 10): digits 0–9; the standard human counting system
- Hexadecimal (base 16): digits 0–9 plus A–F; the most common shorthand for binary data in modern programming
Worked example: binary 1010
Each binary digit represents a power of 2, read right to left: 1010 = (1×8) + (0×4) + (1×2) + (0×1) = 8 + 0 + 2 + 0 = 10 in decimal. The same value is A in hexadecimal and 12 in octal.
Where octal still appears today
Unix and Linux file permissions use octal notation (chmod 755, for example), where each digit represents read/write/execute permissions for owner, group, and others as a 3-bit value — a rare but still-relevant everyday use of a number base that has otherwise mostly fallen out of general use.