Use this Linux chmod permission calculator to quickly convert between numeric (octal) and symbolic formats. For example, entering 755 shows rwxr-xr-x, while selecting u=rwx,go=rx generates the octal value 755. This tool actively helps you understand Linux chmod permissions without memorizing binary tables.

Numeric (octal)

chmod

Symbolic preview

rwxr-xr-x

Symbolic permissions

 

chmod 755 filename Copy

Click any r/w/x button — octal and command update automatically

• First, select the permission type you need: User (Owner), Group, or Others using the toggles above.
• Then, check or uncheck the Read (r), Write (w), and Execute (x) boxes. The calculator instantly shows the corresponding octal number.
• After that, the calculator automatically updates the full chmod command.
• Finally, the generated command appears — use it on your Linux system.

This method works for any Linux chmod permission scenario, whether you’re securing a script or sharing a folder. To learn more about recursive changes, see our advanced chmod guide or the official chmod man page (external).

Understanding Linux chmod permissions starts with three roles: Owner (the file’s creator), Group (users in the file’s group), and Others (everyone else). Each role can have three permission types:

• Read (r) – View file contents or list directory.
• Write (w) – Modify file or add/remove files in a directory.
• Execute (x) – Run a script or enter a directory.

Consequently, the octal value (e.g., 755) combines these permissions. For the Owner, 7 means rwx (read+write+execute). For Group and Others, 5 means r-x (read+execute only).
For instance, chmod 644 myfile.txt gives the owner read+write, but only read access to the group and others. To dive deeper into numeric vs symbolic modes, explore our complete permission tutorial.

Pro tip: Use chmod -R 755 directory/ to recursively apply permissions to all contents.

External reference: GNU Coreutils – chmod invocation