Binary converters
Octal to binary converter.
Octal 755 is binary 111 101 101, and octal 377 is 11111111. Each octal digit expands to exactly 3 bits.
Input
Result
Enter a octal number.
How to octal to binary by hand
Replace every octal digit with its 3-bit pattern: 0 is 000, 1 is 001, 2 is 010, 3 is 011, 4 is 100, 5 is 101, 6 is 110 and 7 is 111.
For 755: 7 is 111, 5 is 101 and 5 is 101, so the permission bits are 111 101 101. The converter prints binary in 4-bit groups, so it shows the same value as 0001 1110 1101.
Worked examples
| Octal | Binary |
|---|---|
7 | 0111 |
17 | 1111 |
101 | 0100 0001 |
377 | 1111 1111 |
755 | 0001 1110 1101 |
Need text, decimal and hex side by side? Use the full binary converter, or look a character up in the ASCII table.
Octal to binary FAQ
How do you convert octal to binary?
Replace each octal digit with its 3-bit binary value and join them. 755 becomes 111 101 101.
What is 777 in binary?
111 111 111, nine 1 bits. As a Unix permission mode it means read, write and execute for everyone.
Do I need the 0o prefix?
No. 377 and 0o377 are both accepted.
Why is the output grouped in fours when octal uses threes?
Binary is shown in 4-bit groups everywhere on this site so it lines up with hex and bytes. The value is identical, only the spaces differ.