Chmod Calculator
Calculate Linux file permissions in numeric and symbolic notation.
=
rw-r--r--
| Read | Write | Execute | |
|---|---|---|---|
| Owner | |||
| Group | |||
| Others |
chmod 644 filename
Key Features
- Calculates Linux file permission values in both numeric (octal) and symbolic (rwx) notation.
- Interactive checkboxes for owner, group, and others read/write/execute permissions.
- Instantly shows the octal number (e.g. 755) as you toggle permissions.
- Displays the equivalent chmod command ready to copy and run in the terminal.
- Explains what each permission level means in plain English.
- Runs entirely in the browser — no data is sent to any server.
Frequently Asked Questions
What does chmod 755 mean?
755 means the owner has read, write, and execute permissions (7), while the group and others have read and execute but not write (5 each). It is a common setting for web server directories.
What is the difference between numeric and symbolic chmod notation?
Numeric notation uses an octal digit per principal (e.g. 644). Symbolic notation uses letters and operators (e.g. u=rw,go=r). Both express the same permissions — this tool shows both simultaneously.
What permissions should I set on web server files?
A common secure baseline is 644 for files (owner can write, everyone can read) and 755 for directories (owner can write, everyone can read and enter). Avoid 777, which gives write access to all users.