What is the Linux Chmod Permission Calculator?
Toggle read/write/execute checkboxes for owner, group, and others, and this calculator immediately shows the resulting octal (e.g. 644) and symbolic (e.g. rw-r--r--) permission string, plus ready-to-copy chmod commands.
How it works
Each checkbox maps to a bit value — read = 4, write = 2, execute = 1 — and the values for owner, group, and other are each summed to build the three-digit octal mode; the same checkbox states are rendered directly as the r/w/x symbolic string.
SysAdmin & security use cases
- Working out exactly what `chmod 777` exposes before running it on a web-facing directory.
- Setting the correct restrictive mode (600) for an SSH private key like `id_rsa`.
- Generating a recursive chmod command for a shared hosting directory without computing the octal by hand.
- Decoding an unfamiliar permission value like 750 seen during a server audit.