Chmod Calculator

Set Unix file permissions interactively; numeric octal and symbolic notation; umask calculator; POSIX ACL reference.

Entity
Read (4)
Write (2)
Execute (1)
Owner
Group
Others
Special

Common presets

644
Octal
rw-r--r--
Symbolic
chmod 644 <file>

Permission bits reference

r
Read (4) — view file contents / list directory
w
Write (2) — modify file / create or delete in directory
x
Execute (1) — run file / enter directory
s
setuid/setgid — run with owner or group privileges
t
Sticky bit — only owner can delete entries in directory

Chmod Calculator

Set Unix file permissions interactively; numeric octal and symbolic notation; umask calculator; POSIX ACL reference.

Common uses

  • Convert 755 to rwxr-xr-x symbolic notation
  • Calculate the umask needed for new files
  • Set read/write for owner only

Also searched as

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  • octal to symbolic permissions
  • rwxr-xr-x to number
  • umask calculator
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  • linux file permissions calculator
  • setuid setgid sticky bit calculator
  • setfacl getfacl reference

Frequently asked questions

What does chmod 755 mean?

It gives the owner read, write and execute, and group and others read and execute (rwxr-xr-x). Toggle the boxes in the Calculator to see it.

How do I convert rwx to a numeric chmod value?

Set the permission checkboxes and the tool shows both octal and symbolic notation.

How do I work out a umask?

The umask Calculator tab shows the permissions new files and directories get for a given umask.

Is there an ACL reference?

Yes, the ACL Reference tab covers POSIX ACLs.

Is my data uploaded to a server?

No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.