Octal to binary converter
Type an octal number to see all its bits, for example permission 755 becomes 111101101.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter octal number.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Replace each octal digit with its fixed 3 bits: 0 = 000, 1 = 001 up to 7 = 111, then drop the extra zeros on the far left.
Example
Inputs: Octal number = 755. Result: Result in binary: 111101101.
755
111101101
Limits and caveats
- Negative numbers keep a minus sign in front of the magnitude; they are not shown in two's complement.
- Up to 2000 digits before the point and 200 after it.
Questions about this tool
Why are 8 and 9 rejected?
Octal uses only the digits 0 to 7. The number eight is written 10 in octal.
What does 644 mean in bits?
644 is 110 100 100: read and write for the owner, read only for the group and others.
Can I type a leading zero like 0755?
Yes. A leading zero does not change the value, and the 0o prefix is accepted too.