Octal to Binary Converter
Convert octal to binary: expand each octal digit to 3 bits. 7₈ = 111₂. Free base-8 to base-2 calculator.
How to Convert Octal to Binary
Replace each octal digit (0–7) with its 3-bit binary equivalent.
Each octal digit → 3 binary bits (pad to 3 if needed).
53₈ → 5=101, 3=011 → 101011₂.
Inverse of binary→octal; used in permissions and low-level work.
Chmod and permission bit patterns. The table and FAQ on this page walk through the factor if you need it.
Conversion Examples
Example: 7 octal to binary
- 7 = 111
111 binary
Single digit.
Example: 53 octal to binary
- 5=101, 3=011 → 101011
101011 binary
Two octal digits.
Common Use Cases
- chmod and permission bit patterns.
- Digital logic labs.
- Decoding octal machine dumps.
- Exam practice.
Frequently Asked Questions
How do you convert octal to binary?
Write each octal digit as a 3-bit binary number and concatenate.
What is 0 octal in binary?
000 (three zero bits).
Octal vs hex for binary?
Octal uses 3 bits per digit; hex uses 4. Hex is more common in modern programming.