FreeDev Tools

Chmod Calculator

Calculate Unix file permission modes with a visual checkboxes UI

Read (4)Write (2)Execute (1)Octal
Owner6
Group4
Others4
Octal value
Symbolic notation
rw-r--r--
chmod command
chmod 644 filename

Common Permissions

Unix file permissions are represented as three sets of three bits: read (r=4), write (w=2), and execute (x=1) for owner, group, and others. The octal value is the sum of the active bits in each set. Common values: 755 gives the owner full permissions while group and others can only read and execute (typical for executables and directories); 644 gives the owner read/write and others read-only (typical for regular files); 600 is private to the owner only (used for SSH keys).

Frequently Asked Questions

chmod (change mode) is a Unix command that sets file or directory permission bits. Permissions control read (r), write (w), and execute (x) access for owner, group, and others.