Toggle rwx for owner, group, and other — or type octal like 755 / 4755.
Three digits → normal modes. Four digits → leading digit sums setuid+setgid+sticky (POSIX).
Comma-split micro-field (POSIX-ish). Applies on top of the current bits/checkboxes.
Who: u g o a (a=all, blank defaults to all for +-, first clause quirks ignored). Letters: r w x X s t · X = execute here.
chmod ??? pathchmod u=rwx,g=rx,o=r pathUmask ripple: your shell subtracts deny bits — e.g. with umask 022 a “full” requested file tends to arrive as owner rw- and group/other r--. This calculator shows final mode bits once; it does not know your interactive umask unless you subtract mentally.
umask never removes setuid/setgid bits that chmod asks for — but distro defaults rarely hand out set-bits on ordinary files anyway.