Octal to Binary Converter
Convert octal digits (base 8) to binary bits (base 2) with 3-bit expansions.
How to use it
- Enter octal digits to convert to binary.
Examples
| 377 | 11111111 |
Each octal digit (0-7) expands to exactly 3 binary bits, since 8 = 2³. That makes octal-to-binary a direct lookup: convert each digit individually to its 3-bit binary value and concatenate them.
Worked example
377: 3 = 011, 7 = 111, 7 = 111. Concatenated: 011 111 111, which strips the leading zero to 11111111.
Where this comes up
- Expanding a Unix chmod permission value (like 755) down to its raw binary read/write/execute bits
- Working with legacy systems or embedded code that stores values in octal
- Computer science coursework covering the relationship between octal and binary
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Last updated 18 August 2026