DEVELOPER TOOL

chmod Calculator

Toggle permissions visually and get the octal code, symbolic notation, and full chmod command instantly. Supports setuid, setgid, and sticky bit.

100% client-side Real-time updates Special bits support

Permissions

Read
Write
Execute
Owner
r
w
x
Group
r
w
x
Other
r
w
x
Special Bits
setuid
s
setgid
s
sticky
t

Reverse Lookup

Type an octal number to see its permission breakdown.

Options

File type

Affects the first character in ls -la output

Filename

Used in the chmod command and ls preview

Output

Octal
0000
Symbolic
---------
Command
chmod 000 myfile.sh
ls -la Preview
---------- 1 user group 4096 Feb 15 10:30 myfile.sh

Common Presets

Permission Reference

r
Read (4)

View file contents or list directory entries. Octal value 4. Without this, you can't cat a file or ls a directory.

w
Write (2)

Modify file contents or add/delete directory entries. Octal value 2. For directories, this allows creating and deleting files inside.

x
Execute (1)

Run the file as a program or cd into a directory. Octal value 1. Scripts need both read and execute permissions.

Special Bits

setuid (4xxx)

When set on an executable, it runs with the file owner's privileges. Example: /usr/bin/passwd

setgid (2xxx)

Executable runs with the file's group privileges. On directories, new files inherit the directory's group.

Sticky bit (1xxx)

On directories, only the file owner can delete their files. Classic example: /tmp uses mode 1777.

Copied!

Related Tools