About the Octal Converter
Convert octal to decimal, binary and hexadecimal — useful for Unix file permissions.
Also known as: octal to decimal, decimal to octal, base 8 converter, chmod calculator.
How to use this calculator
- Enter value, input base.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Each octal digit represents exactly 3 bits
Worked example
Using the values pre-filled in the calculator above:
- Value: 755
- Input base: Octal
the calculator returns:
- Octal: 755
- Decimal: 493
- Binary: 111101101
- Hexadecimal: 1ED