Chmod Calculator

Calculate Unix file permissions interactively. Toggle checkboxes or enter a numeric value to convert between formats.

or use the checkboxes below
EntityReadWriteExecuteOctalSymbolic
User (Owner)7rwx
Group5r-x
Others5r-x
Numeric
755
Symbolic
rwxr-xr-x
Command
chmod 755 file
ls -l output preview
-rwxr-xr-x 1 user group 4096 Apr 2 12:00 filename

Common Permissions

About Chmod Calculator

This free online chmod calculator helps you compute Unix/Linux file permissions. Toggle read, write, and execute permissions for user, group, and others to see the numeric (octal) and symbolic notation instantly.

Understanding Unix Permissions

Every file and directory in Unix/Linux has three permission sets: one for the owner (user), one for the group, and one for everyone else (others). Each set can have read (r=4), write (w=2), and execute (x=1) permissions.

Numeric vs. Symbolic Notation

  • Numeric (octal): Three digits (e.g., 755), each the sum of read (4) + write (2) + execute (1)
  • Symbolic: Nine characters (e.g., rwxr-xr-x) showing permissions for user, group, and others

Common Permission Values

  • 755 — Standard for executables and directories
  • 644 — Standard for regular files
  • 700 — Private directories (owner only)
  • 600 — Private files like SSH keys