Octal to binary converter
Enter a value that uses digits 0–7.
Convert an octal number to binary.
About this tool
The octal to binary converter expands a base 8 number into zeros and ones. Use it to inspect Unix permission bits, study how number bases relate, or prepare a binary mask from an octal value. Each octal digit maps to three binary digits, so the conversion is easy to check by hand. Enter a whole value containing digits from zero through seven.