Free online Linux file permission calculator. Parse ls -la output (drwxr-xr-x), convert between numeric and symbolic modes, calculate umask, handle SUID/SGID/Sticky Bit. Essential tool for sysadmins and developers. | No sign-up · Data never leaves your browser
Zero dependencies · Works offline🔧 Permission Calculator
📊 Permission Reference Table
| Numeric | Symbolic | Permission | Common Use |
|---|---|---|---|
| 777 | rwxrwxrwx | All permissions for everyone | Temp dirs (not recommended) |
| 755 | rwxr-xr-x | Owner all, others read+exec | Directory/script default |
| 700 | rwx------ | Owner only | Private directory |
| 644 | rw-r--r-- | Owner rw, others read | File default |
| 600 | rw------- | Owner rw only | Private file (SSH keys) |
| 400 | r-------- | Owner read only | Read-only config |
| 4755 | rwsr-xr-x | SUID + 755 | passwd, privileged commands |
| 1777 | rwxrwxrwt | Sticky + 777 | /tmp directory |
How to Use Linux File Permission Calculator
The Linux File Permission Calculator supports 4 modes:
- Parse ls Output
Paste the permission field from ls -la (e.g., drwxr-xr-x or -rw-r--r--) to automatically parse numeric, symbolic, and chmod command. - Numeric Mode
Enter numeric permissions (e.g., 755, 644) to convert to symbolic and ls format. Supports special bits (SUID/SGID/Sticky). - Symbolic Mode
Enter symbolic permissions (e.g., u=rwx,g=rx,o=r) to convert to numeric and ls format. - Umask Calculator
Enter a umask value to calculate default permissions for new files and directories.
❓ FAQ
What does drwxr-xr-x mean?
drwxr-xr-x represents a directory where the owner has read, write, and execute permissions (rwx), the group has read and execute (r-x), and others have read and execute (r-x). The numeric value is 755, the standard permission for directories.
What is umask and how is default permission calculated?
umask is a mask that controls default permissions for newly created files and directories in Linux. Default permission = base permission - umask. Files have a base of 666, directories 777. For example, with umask=022, new files get 666-022=644 (rw-r--r--) and new directories get 777-022=755 (rwxr-xr-x).
What are SUID, SGID, and Sticky Bit?
SUID (4000) makes a program run with the file owner's permissions, like the passwd command. SGID (2000) makes a program run with the file's group, and on directories new files inherit the directory's group. Sticky Bit (1000) only allows the file owner and root to delete files in a directory, commonly used on /tmp.