chmod Calculator converts rwxr-xr-x style permissions to octal values like 755 and back again. It is useful for Linux, server setup, deployment notes, and shell commands.
Convert Unix file permissions between rwx notation and octal chmod values. Everything runs locally in this tab.
755
Yes. The tool is free and runs directly in your browser with no account required.
No. Processing happens locally in the browser tab. Your input is not sent to a server.
It is best for converting between rwx-style permission strings and octal chmod numbers when writing deployment scripts, Dockerfiles, or server setup notes.
It checks the input pattern: if you type 3 or 4 digits from 0-7 (like 755 or 0644), it converts octal to rwx notation. If you type an rwx-style string (like rwxr-xr-x), it converts that to octal.
The 4-digit octal form is accepted as input, but only the last three digits (owner/group/other) are converted to rwx — the special-permissions digit is not reflected separately in the rwx output.
The tool scans for rwx-pattern triplets anywhere in the string, so a leading -, d, or l character is simply ignored and the three permission groups after it are still converted correctly.
No. The tool works on a single value at a time — one octal number or one rwx string per conversion. Paste one value, read the result, then replace it with the next.
Each digit is the sum of read (4), write (2), and execute (1) for one permission group — owner, group, then others. For example, 6 means read+write (4+2), and 7 means read+write+execute (4+2+1).
