Chmod Calculator

Translates Unix file permission bits between three representations: a checkbox grid (owner/group/other x read/write/execute), the 3-digit octal code, and the 9-character symbolic string (rwxrwxrwx). It also emits a ready-to-copy 'chmod NNN filename' command and offers one-click common presets.

1. Toggle the read/write/execute checkboxes for Owner, Group, and Other; the octal/symbolic/command outputs update live. 2. Or type a 3-digit octal into the Direct Input field to set the checkboxes from it. 3. Or click any preset button (755, 644, 777, 600, 700, 750, 664, 400) to apply it instantly. 4. Click Copy next to the command to copy 'chmod NNN filename' to the clipboard.

Each role's octal digit is the sum of read=4, write=2, execute=1. So 7 = rwx, 6 = rw-, 5 = r-x, 4 = r--, 0 = ---. Common useful presets: 755 (rwxr-xr-x, executables/dirs), 644 (rw-r--r--, regular files), 600 (rw-------, private files), 700 (rwx------, private dirs), 400 (read-only secrets). The symbolic view uses 'r', 'w', 'x', or '-' for absent bits.