Chmod Calculator

Chmod Calculator features

• 01

  Three views, always in sync

  The checkbox grid, octal digits, and symbolic rwx string are three windows onto the same permissions. Change one and the others follow, so you can work in whichever notation you think in.

• 02

  Special bits included

  setuid, setgid, and the sticky bit are first-class toggles, and the symbolic output shows them correctly as s, S, t, or T — details most quick calculators skip.

• 03

  Copy the command

  The tool assembles the full chmod command and offers one-click presets like 644 for files and 755 for directories, each labelled so you know exactly what it grants.

Chmod Calculator FAQ

What does chmod 777 mean?

777 grants read, write, and execute to everyone — owner, group, and other. Each 7 is 4 (read) + 2 (write) + 1 (execute). It's rarely a good idea on real files because anyone can modify them; 755 or 644 is usually what you actually want.

What is the difference between chmod 755 and 644?

755 (rwxr-xr-x) lets the owner read, write, and execute while everyone else can read and execute — the standard for directories and scripts. 644 (rw-r--r--) lets the owner read and write while others only read — the standard for regular files.

How do I convert symbolic permissions to octal?

Type the symbolic string (like rwxr-xr-x) into the symbolic field and the octal value appears instantly. Each rwx triad maps to a digit: r=4, w=2, x=1, added together per group.

What are the setuid, setgid, and sticky bits?

They're a leading fourth octal digit. setuid (4) runs a file as its owner, setgid (2) runs it as its group or makes new files inherit a directory's group, and the sticky bit (1) — common on /tmp — stops users deleting each other's files. Toggle them here to see the symbolic s/t markers.

Does this calculator send anything to a server?

No. All conversion is done in your browser with plain arithmetic. Nothing you enter is uploaded.