Unix Permission Calculator (chmod)
Interactively calculate Unix file permissions (octal and symbolic) and generate chmod commands.
About Unix Permission Calculator (chmod)
What it’s for
On Unix/Linux, permissions control who can do what. They’re shown in two notations: symbolic (e.g., -rwxr-xr--) and octal (e.g., 754). This calculator turns one into the other and generates ready‑to‑copy chmod commands so you don’t miscalculate 4+2+1 by hand.
This tool provides a simple, interactive way to understand and calculate Unix file permissions. Ticking the checkboxes for Read (r), Write (w), and Execute (x) for each user type (Owner, Group, Others) will instantly update the Octal and Symbolic notations, and generate the corresponding chmod command.
How to use
- Interactive Grid: Check the boxes for Owner, Group, and Others. The Octal, Symbolic, and
chmodcommand will update instantly. - Direct Input: Type a valid octal code (e.g., 755, 644) into the "Octal" box to see which permissions it represents.
- Presets: Use the preset buttons for common scenarios like web files (644), directories (755), or sensitive files (600).
- Special Permissions: Use the checkboxes for SetUID, SetGID, and Sticky bit for advanced cases.
Common Scenarios
- Web Files (644):
rw-r--r--— Owner can read/write, everyone else can only read. Use the "File (644)" preset. - Directories & Scripts (755):
rwxr-xr-x— Owner can do anything, everyone else can read and enter/execute. Use the "Directory/Script (755)" preset. - Sensitive Files (600):
rw-------— Only the owner can read/write. Essential for files with passwords or keys. Use the "Sensitive File (600)" preset.
Reference this content, page, or tool as:
"Unix Permission Calculator (chmod)" at https://MiniWebtool.com/unix-permission-calculator/ from MiniWebtool, https://MiniWebtool.com/
by miniwebtool team. Updated: Sep 25, 2025