Tick Read, Write, and Execute for Owner, Group, and Others, and instantly get the octal value, symbolic notation, and ready-to-copy chmod command. Free, no signup, runs in your browser.
| User Type | Read (4) | Write (2) | Exec (1) | Value |
|---|---|---|---|---|
| 👤 Owner | 7 | |||
| 👥 Group | 5 | |||
| 🌐 Others | 5 |
Octal Value
Symbolic Notation
chmod 755 filename
Permission Breakdown
chmod (change mode) is the Unix and Linux command that controls who can read, write, and execute a file or directory. Every file has three sets of permissions — for the Owner, the Group, and Others (everyone else) — and each set can grant Read (r), Write (w), and Execute (x).
If you've ever looked at chmod 755 and wondered what the digits mean, this calculator removes the guesswork. Tick the boxes for the access you want, and it builds the octal value, the symbolic string, and the exact command to run — no memorizing number combinations.
Each permission has a value: Read = 4, Write = 2, Execute = 1. Add them up for each user type to get a single digit from 0 to 7. So full access (read + write + execute) is 4 + 2 + 1 = 7; read and execute only is 4 + 1 = 5. Line up the three digits — Owner, Group, Others — and you get a value like 755, which means rwxr-xr-x.
For directories, the Execute bit has a special meaning: it controls whether you can enter the directory (cd into it). A directory without execute can't be navigated into, even with read permission — a common source of confusion.
| Value | Permissions | Typical Use |
|---|---|---|
| 755 | rwxr-xr-x | Web server directories, public scripts |
| 644 | rw-r--r-- | Regular files, web pages, CSS/JS |
| 777 | rwxrwxrwx | ⚠ Avoid — full access to everyone (security risk) |
| 600 | rw------- | SSH private keys, sensitive config |
| 700 | rwx------ | Private executable scripts |
| 440 | r--r----- | Config files with credentials |
For most sites, set directories to 755 and files to 644 — that gives the owner full control while letting the server read what it needs. Lock down sensitive files like wp-config.php and .env to 600 or 640 so only the owner can read them. Upload directories sometimes need 755 or 775 to allow writing — but never use 777, which lets anyone modify or execute files and is a serious security hole.
Visual Builder
Tick boxes instead of memorizing octal numbers.
Instant Octal
Octal value, symbolic notation, and command update live.
Quick Presets
One-click 755, 644, 700, and 777 for common cases.
Copy Anything
Click the value, the notation, or the full command to copy.
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Keyboard Shortcuts
Ctrl/Cmd + 1–4 apply presets; Ctrl/Cmd + C copies the command.
chmod -R 755 /path/to/directory to apply a value to a directory and everything inside it. Be careful applying the same value to both files and directories recursively.