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Unix Permissions Calculator - Convert between chmod numeric and symbolic notation
Convert between chmod numeric and symbolic notation
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
What does 755 mean?
Owner: read+write+execute (7), Group: read+execute (5), Others: read+execute (5).
When to use 644 vs 755?
644 for files (rw-r--r--), 755 for directories and executables (rwxr-xr-x).
What about special permissions?
setuid (4), setgid (2), sticky (1) can be added as 4th digit: 4755 for setuid.
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About this tool
This Unix Permissions Calculator turns your inputs into practical results. Provide Numeric (e.g., 755), Owner Read, and Owner Write to calculate Numeric Notation and Symbolic Notation.
Adjust values to compare scenarios and see how sensitive the result is. The calculation uses the numbers as entered, so double-check units and expect small differences from rounding in the displayed totals.