Chmod Calculator

Calculate Unix file permissions visually using chmod

rwxr-xr-x

Owner

Group

Others

Owner

7

rwx

Group

5

r-x

Others

5

r-x

What is a Chmod Calculator?

A chmod calculator is a free online tool for calculating the numeric and symbolic representations of Unix file permissions. It helps you visualize permissions and generate the correct syntax for the chmod command. All calculations happen in the browser.

How to calculate permissions

Click the permission checkboxes to set the desired permissions for owner, group and others. The calculator shows the numeric (like 755) and symbolic (like rwxr-xr-x) representations in real time.

Understanding permissions

Permissions are grouped into three classes: owner, group and others. Each class can have read (r, value 4), write (w, value 2) and execute (x, value 1) permissions. These values are added together to get the number for each class.

Common permission modes

  • 755 (rwxr-xr-x) - Directories and executable files
  • 644 (rw-r--r--) - Regular files
  • 700 (rwx------) - Private directories
  • 600 (rw-------) - Sensitive files
  • 777 (rwxrwxrwx) - Full permissions (use with caution)

Frequently Asked Questions

What is chmod?+
chmod is a command in Unix and Unix-like systems (such as Linux and macOS) used to change the permissions of files or directories. Permissions determine who can read, write or execute a file.
How do permissions work?+
Permissions are grouped into three classes: owner, group and others. Each class can have read (r, value 4), write (w, value 2) and execute (x, value 1) permissions. These values are added together to get the numeric representation (like 755).
How do I use the chmod calculator?+
Click the permission checkboxes to set the desired permissions for owner, group and others. The calculator shows the numeric and symbolic representations in real time.
What is the difference between numeric and symbolic representations?+
The numeric representation uses three digits (like 755), where each digit is the sum of the permission values. The symbolic representation uses letters (like rwxr-xr-x), where r means read, w means write, x means execute and - means no permission.
What are common permission settings?+
755 (rwxr-xr-x) for directories and executable files, 644 (rw-r--r--) for regular files, 700 (rwx------) for private directories, and 600 (rw-------) for sensitive files.
Can I set special permissions?+
This calculator handles basic permissions. Special permissions (such as setuid, setgid and the sticky bit) require an additional fourth digit in the numeric representation.

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Chmod Calculator — free online chmod calculator, file permission calculator, unix permissions, chmod numbers, chmod symbols, linux permissions, file permission settings, chmod conversion. No signup required. Works in your browser.