Chmod Calculator

Tick what each group may do and read the octal off the top, or type the octal and watch the boxes fill in.

Permissions

Who

Read

Write

Execute

Owner

Group

Everyone

Special bits setuid run as the file’s owner setgid run as the file’s group, or inherit it on a directory sticky only the owner can delete, the /tmp rule

Result

644

rw-r--r--

Or type it in

Three or four octal digits, such as 755 or 4755.

Or the symbolic form

Common settings

What the numbers mean

4: read — open the file, or list a directory
2: write — change the file, or add and remove entries in a directory
1: execute — run the file, or enter a directory
Add them: read plus write is 6, all three is 7, read plus execute is 5