chmod Calculator – Calculate Linux File Permissions Numerically and Symbolically
The chmod calculator converts Linux/Unix file permissions between numeric (e.g., 755) and symbolic formats (e.g., rwxr-xr-x). The tool explains each bit's meaning in an understandable way.
Select desired permissions for owner, group, and others by checking read (r), write (w), and execute (x) bits, and the calculator shows the corresponding numeric code and chmod command. You can also enter a number to get the symbolic representation.
What do chmod 755 and 644 mean?
chmod 755 means: owner has all permissions (rwx), group and others have read and execute (r-x). It's typical for directories and executable files. chmod 644 gives owner read and write (rw-) and everyone else read-only (r--) — typical for web server files and documents.
Loading tool...
Not sure what to try next?
Browse all tools →The chmod calculator helps generate correct file permissions for Linux and Unix environments. An indispensable tool for developers and administrators managing servers.
Select the desired read, write, and execute permissions for user, group, and others – the calculator produces the corresponding chmod number and command.
- Convert permissions (rwx) to numeric format (e.g., 755) or vice versa.
- Clearly see who can read, write, and execute the file.
- Copy the ready chmod command directly to the terminal.
The chmod number consists of three digits, each describing different user group permissions.
- First digit = file owner, second = group, third = others.
- Most common permissions: 644 (files), 755 (directories and scripts).
- Overly permissive rights (e.g., 777) are a security risk.
Incorrect file permissions can cause malfunctions or security issues.
- Avoid setting permissions to 777 unless absolutely necessary.
- Web server files usually require specific permissions to function.
- Test permission changes in a testing or development environment first.