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Chmod Calculator

Calculate Unix/Linux file permissions with visual checkboxes. Convert between numeric and symbolic modes. Free.

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Owner

Group

Others

Symbolic notation
rwxr-xr-x
Command
chmod 755 filename
Owner 7 rwx
Group 5 r-x
Others 5 r-x

Common presets

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Linux Chmod Permission Calculator

The Linux Chmod Permission Calculator is a free online tool that converts between numeric (octal) and symbolic file permission notations used in Unix and Linux systems. Enter a three-digit octal permission code like 755 and instantly see its symbolic representation (rwxr-xr-x), or toggle individual read, write, and execute checkboxes for owner, group, and others to compute the corresponding octal code. This eliminates the mental arithmetic of calculating permission values manually.The calculator displays a clear breakdown showing exactly which permissions are granted to the owner (user), group, and others (world). Each digit in the octal notation represents the sum of permissions: read (4), write (2), execute (1). For example, 755 means the owner has full access (7 = 4+2+1 = rwx), while group and others have read and execute only (5 = 4+1 = r-x). The tool also generates the complete chmod command ready to paste into your terminal.System administrators use this tool to set secure file permissions on web servers, application directories, and configuration files. DevOps engineers calculate permissions for deployment scripts and CI/CD pipelines. Developers determine the correct permissions for executable scripts, log files, and upload directories. Students learning Linux administration find the visual toggle interface invaluable for understanding how permission bits work.Linux Chmod Calculator is part of the facilita.tools suite of free developer utilities. Available in Portuguese, English, and Spanish, it works on any modern browser and adapts to mobile devices.

Frequently Asked Questions

What is chmod in Linux?
Chmod (change mode) is a Linux/Unix command that sets file and directory permissions. It controls who can read, write, or execute a file using a 3-digit octal number (e.g., 755) or symbolic notation (e.g., rwxr-xr-x).
What does chmod 755 mean?
Chmod 755 gives the owner full permissions (read+write+execute), while group and others get read and execute only. This is the standard permission for web directories and executable scripts.
What is the difference between chmod 644 and 755?
644 (rw-r--r--) allows the owner to read/write while others can only read. 755 (rwxr-xr-x) adds execute permission. Use 644 for regular files and 755 for directories and scripts.