Chmod Calculator
Tick the permissions or type an octal number — get the chmod command and symbolic notation both ways.
rwxr-xr-xsymbolic
chmod 755command
Common permission modes
| Octal | Symbolic | Typical use |
|---|---|---|
| 755 | rwxr-xr-x | Directories, scripts, executables |
| 644 | rw-r--r-- | Regular files, web pages, images |
| 600 | rw------- | Private keys, credentials, .env files |
| 700 | rwx------ | Private directories (~/.ssh) |
| 664 | rw-rw-r-- | Group-collaborative files |
| 777 | rwxrwxrwx | Almost never right — see below |
Frequently asked questions
How does the octal number work?
Each digit is owner, group, others in order; each is read (4) + write (2) + execute (1). So 7 = rwx, 6 = rw-, 5 = r-x, 4 = r--. 755 means the owner can do everything, everyone else can read and execute.
Why is chmod 777 a bad idea?
It lets every user and process on the system modify the file — malware and misbehaving scripts included. If something "only works with 777", the real issue is usually the file's owner; fix it with chown instead.
What does execute mean on a directory?
Permission to enter it and access files inside. A directory with read but no execute lets you list names but not open anything — which is why directories are 755 where files are 644.
Last updated: 2026-07-13