See the permissions new files and directories get under a umask such as 022
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.A umask decides the permissions of every file and directory a program creates. New files start from 666 and directories from 777, and each bit set in the umask is taken away: 022 removes write for group and others, giving 644 files and 755 directories. Type a umask to see both results, then use the calculator above to compare them with the mode you want.
Open the page with umask 022 already entered.
Type your umask, or pick a common one from the chips beside the box.
Read New files (666 minus umask) and New directories (777 minus umask).
Press Use beside either result to load it into the calculator above and copy its chmod command.
This chmod calculator converts Unix and Linux file permissions between the octal number, such as 755, and the symbolic letters that ls -l prints, such as rwxr-xr-x. Tick the read, write and execute boxes for the owner, the group and everyone else, type a number, or paste the permission column from ls -l, including the leading file type letter; all three stay in step.
Each digit is a sum: read is 4, write is 2 and execute is 1. The owner's 7 is 4 + 2 + 1, the group's 5 is 4 + 1. A fourth digit in front holds the special bits: setuid (4) runs a program as its owner, setgid (2) runs it as its group or makes a directory's new files inherit the group, and sticky (1) lets people delete only their own files in a shared directory like /tmp. In the letters these show as s or t in the execute position, and as a capital S or T when execute is not also set, which usually means a mistake.
The umask box shows what a umask does to new files, which start from 666, and new directories, which start from 777. A umask of 022 gives 644 and 755; 077 gives 600 and 700.
The rest of the article, and all 6 questions about Chmod Calculator, are on the Chmod Calculator page.
Both let only the owner write. 755 adds execute for everyone, which a script, a program or a directory needs; 644 leaves execute off, which suits ordinary files such as web pages, images and configuration. Giving a plain file 755 is harmless but unnecessary.
Mode 777 lets every user on the machine change, replace or delete the file, and run it. On a web server that means any compromised process can rewrite your code. Directories that really must be shared should use 1777, which adds the sticky bit so people can delete only their own files.
Programs normally create files with 666 and directories with 777, and every bit set in the umask is removed. With umask 022, files come out as 644 and directories as 755. With 077 they are 600 and 700, private to the owner. A umask never adds permissions.
No. The page only works out the numbers and writes the command for you to run in a terminal. Nothing is uploaded and no file is touched. Paste the command into a shell on the machine that holds the file, adding sudo if you do not own it.
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