Unix Permissions Calculator (chmod)
File permissions in Unix/Linux systems determine who can read (r), write (w), and execute (x) a file. Permissions are set for three categories: Owner, Group, and Others. This calculator converts between numeric and symbolic permission formats.
How File Permissions Work Each permission has a numeric value: read (r) = 4, write (w) = 2, execute (x) = 1. Permissions for each category are summed: rwx = 4+2+1 = 7, r-x = 4+0+1 = 5. The number 755 means rwxr-xr-x: the owner has full access, while group and others can read and execute. All calculations happen locally in your browser.
Owner
Group
Others
Common Permissions
| chmod | rwx | Description |
|---|---|---|
| 777 | rwxrwxrwx | Full access for all |
| 755 | rwxr-xr-x | Owner full, others read+execute |
| 750 | rwxr-x--- | Owner full, group read+execute |
| 700 | rwx------ | Owner only |
| 666 | rw-rw-rw- | Read+write for all |
| 644 | rw-r--r-- | Owner read+write, others read |
| 600 | rw------- | Owner read+write only |
Free online Unix file permissions calculator (chmod). Use interactive checkboxes to visually select Read, Write, and Execute permissions for Owner, Group, and Others. Numeric (e.g., 755) and symbolic (e.g., rwxr-xr-x) formats are synchronized in real time.
In Unix/Linux systems, every file and directory has three sets of access permissions: for the owner, group, and other users. Each permission has a numeric value: read (r) = 4, write (w) = 2, execute (x) = 1. The chmod 755 combination is one of the most common for executable files and directories.
The calculator supports two-way synchronization: change the checkboxes, enter a number, or type a symbolic string — all other fields update instantly. A table of common permission combinations helps you quickly find the right setting. An indispensable tool for system administrators and developers working with Linux servers.