Chmod calculator
Toggle rwx bits ↔ octal ↔ symbolic permissions.
Runs in this tab. The file stays here.
This runs in your browser. Nothing is uploaded.
About Chmod calculator
Toggle Unix rwx permission bits and see octal and symbolic modes (for example 755 ↔ rwxr-xr-x) offline.
chmod math is muscle memory until it is not — especially when you are teaching someone else or double-checking a deploy script. This calculator maps the classic nine permission bits to octal and symbolic forms so you can flip owner/group/other read-write-execute without opening a man page.
Click bits or type an octal mode and watch the other representation update. Three-digit modes only: setuid, setgid, and sticky are out of scope here so the UI stays honest about what it covers.
Subnet calculator is for IPv4 CIDR math. Gitignore generator helps ignore files, not permission bits. Neither replaces knowing why 600 vs 644 matters on a secrets file.
How to use Chmod calculator
- 1Toggle rwx bits for user, group, and other — or type an octal mode.
- 2Read the matching symbolic and octal representations.
- 3Copy the mode into your chmod command or docs.
What it won't do
- Three-digit modes only — no ACL editor.
- Display helper, not a remote SSH tool.
Common questions
Does the chmod calculator include setuid, setgid, or sticky?
No. It focuses on the common three-digit rwx triad. Special bits need a four-digit mode you can still type by hand in the shell.
Is 755 the same as rwxr-xr-x?
Yes. Owner read/write/execute, group and other read/execute — the usual directory default on many systems.
Does this change permissions on my machine?
No. It only shows the mode string. You still run chmod locally.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation