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Chmod Calculator

Toggle permissions or type an octal value. See the numeric, symbolic, and command output instantly.

Permission Toggles

ReadWriteExecuteValue
Owner7
Group5
Other5
Octal Value
Symbolic Notation
rwxr-xr-x
Command
chmod 755 <file>

Common Presets

How to Calculate Unix File Permissions

Unix permissions are easier to reason about as rwx bits than as a three-digit octal. This chmod calculator toggles read, write, and execute for owner, group, and other, then shows the octal and symbolic forms you pass to chmod.

It runs in the browser with no filesystem access — it only generates the mode string. Use it when you are writing Dockerfiles, Ansible tasks, or install docs and need 644 vs 755 vs 600 without guessing.

Tips

  • 755 is typical for executables and directories; 644 for files; 600 for private keys.
  • The execute bit on directories means “can enter / list depending on read”.
  • Sticky and setuid bits are not the focus here — this calculator covers the common nine-bit mask.

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