Linux / chmod

chmod Permission Calculator

Convert Linux file permissions between checkboxes, octal values, symbolic notation, and chmod commands.

Permission matrix

Special bits: setuid (4) setgid (2) sticky (1)

Octal Symbolic notation

All calculations run locally. Octal supports 3 digits (755) or 4 digits with special bits (4755).

Command

chmod 000 file

Click a command above to copy it to the clipboard.

Permission reference

Number	Symbolic	Description
644	rw-r--r--	Common file default：owner can read and write; others can read
755	rwxr-xr-x	Common for directories and scripts：owner has full access; others can read and execute
600	rw-------	Private file：only the owner can read and write (required for SSH private keys)
700	rwx------	Private directory：only the owner can enter and access
775	rwxrwxr-x	Shared directory：group members can write
664	rw-rw-r--	Shared file：group members can edit
777	rwxrwxrwx	Anyone can read, write, and execute——high risk; do not use in production

Click any row to apply that permission.

About chmod Permission Calculator

Toggle permission bits or enter an octal or symbolic mode, then copy the resulting chmod command.

What do the special permission bits mean?

Setuid, setgid, and the sticky bit change permission behavior beyond read, write, and execute. Review their implications before applying them to real files.

Subject	Read r (4)	Write w (2)	Execute x (1)
Owner (u)
Group (g)
Others (o)