chmod Calculator

A chmod calculator is an interactive tool that helps you compute Unix/Linux file permissions in both octal (numeric) and symbolic notation. The chmod command controls who can read, write, and execute files on Unix-like systems — but remembering the numeric codes can be tricky.

This chmod calculator online lets you toggle permission bits visually for owner, group, and other users, instantly showing the corresponding octal value (e.g., 755) and symbolic string (e.g., rwxr-xr-x). You can also type an octal or symbolic value and see the permission grid update in real time.

Whether you're setting up a web server, deploying scripts, or hardening file security, this tool eliminates guesswork. It runs entirely in your browser — no data is sent to any server.

1. Toggle permission checkboxes — Click the read (r), write (w), and execute (x) boxes for Owner, Group, and Other to build your permission set visually.
2. Enter an octal value — Type a three-digit octal number (e.g., 644) in the input field to see the corresponding permission grid and symbolic notation.
3. Use presets — Click common presets like 755, 644, or 777 to quickly set standard permission configurations.
4. Copy the result — Copy the octal value or full chmod command to your clipboard with one click.

• Visual permission grid — Interactive checkboxes for read, write, and execute across owner, group, and other.
• Octal ↔ symbolic conversion — Instantly converts between numeric (e.g., 755) and symbolic (e.g., rwxr-xr-x) notation.
• Common presets — One-click presets for standard permissions like 755, 644, 600, 777, and more.
• Command generation — Generates the complete chmod command ready to paste into your terminal.
• 100% client-side — Your data never leaves your browser. No server requests, no logging.

• Web server deployment — Set correct permissions for web files (644 for files, 755 for directories) to ensure security while maintaining access.
• Script execution — Make shell scripts executable with chmod 755 script.sh or restrict to owner-only with chmod 700.
• SSH key permissions — Set required permissions for SSH keys (chmod 600 ~/.ssh/id_rsa) and directories (chmod 700 ~/.ssh).
• Shared hosting setup — Configure file permissions for shared environments where group and other access must be carefully controlled.
• Security auditing — Verify that sensitive files don't have overly permissive settings like 777.