Linux permissions can be confusing. `chmod` (change mode) uses a 3-digit number to define permissions. The first digit is for the Owner, the second for the Group, and the third for Everyone else. Each digit is the sum of permissions: Read (4) + Write (2) + Execute (1). This tool does that addition for you.

1. Check the boxes for Read (r), Write (w), and Execute (x) for Owner, Group, and Public.
2. Watch the numeric value (e.g., 777) update instantly.
3. See the command string update in real-time.
4. Copy the full `chmod` command to use in your terminal.

• Setting a web server file to be readable but not writable by the public (644).
• Making a script executable so you can run it (755).
• Locking down a config file so only the owner can read it (600).
• Learning how Linux file security works.

• Visual Interface: No need to memorize octal math; just point and click.
• Dual Output: Generates both octal (755) and symbolic (rwxr-xr-x) formats.
• Terminal Ready: provides the full command line to copy-paste.
• Explanation Grid: Helps you understand what each permission bit means.

Unix file systems treat permissions as bits. Read is the 4-bit, Write is the 2-bit, and Execute is the 1-bit. By adding these values (e.g., 4+2+1 = 7), the system knows exactly what access is allowed. This calculator is essentially a visual binary-to-octal converter specific to file modes.

All calculations and data processing for this tool are performed locally in your browser. UtilToolkits does not send any of your data to an external server, ensuring your information remains private and secure.