CHMOD Calculator for Unix and Linux

What this tool does

The CHMOD calculator converts classic Unix and Linux permissions between numeric and symbolic notation.

It explains regular rights, special bits, symbolic operations and notable combinations for files and directories.

Enter a 3- or 4-digit octal value, a symbolic permission string or permissions through the checkboxes.
Choose an object type and optionally a name for the generated shell command.
Use operations, comparisons and presets for further calculations.

Check why rw-r--r-- corresponds to 644.
Convert values such as 4755 or 1777 including Setuid, Setgid and the sticky bit.
Create a readable numeric or symbolic chmod command line.

The tool does not change files or execute shell commands.
Permissions have different meanings on directories and regular files; notes follow the selected object type.
POSIX ACLs, SELinux, AppArmor, ownership, group membership and mount options are not evaluated.

What does the value 755 mean?

The Owner can read, write and execute; Group and Others can read and execute.

Does the calculator change actual file permissions?

No. It only calculates values and commands for manual use and never executes shell commands.