alt/repo
alternative-repository
ALTREPO/Calculators/CHMOD CALCULATOR: LINUX FILE PERMISSIONS

Chmod Calculator: Linux File Permissions

Instantly calculate Linux file permissions. Bi-directional syncing means you can check the boxes, type the octal value, or enter symbolic letters - everything updates live. Copy the exact bash command instantly.

chmod 755
Owner can read, write, and execute. Group can read and execute. Public can read and execute.
Scope Read (4) Write (2) Execute (1)
Owner
Group
Public
Octal Format
Symbolic Format
Common Presets
Linux Permissions Architecture A premium conceptual diagram illustrating Owner, Group, and Public permission layers locking a directory. -rwxr-xr-x chmod 755 app.sh OWNER 7 rwx (4+2+1) GROUP 5 r-x (4+0+1) PUBLIC 5 r-x (4+0+1)
File permissions establish a secure boundary around your code.
Every digit assigns exact Read (4), Write (2), and Execute (1) rules to a specific tier of users.

Chmod calculator FAQ

Understanding Linux file permissions can be tricky at first, but it essentially comes down to three groups of people (the Owner, the Group, and the Public) and three types of actions they can take (Read, Write, and Execute). The chmod command uses a 3-digit octal number - like 755 or 644 - as a shorthand way to represent the exact combination of these permissions. Use the interactive calculator above to instantly translate between the visual checkboxes, the octal numbers, and the symbolic letters.

What does chmod do?

chmod (change mode) is a Unix/Linux command used to change the access permissions of file system objects (files and directories). It controls who can read, write, or execute a file.

How to use chmod?

You use chmod by opening a terminal and typing chmod followed by the permissions (either octal like 755, or symbolic like +x) and the target filename. For example: chmod 755 my_script.sh

What does chmod 777 do?

chmod 777 gives completely open access to a file or directory. It grants read, write, and execute permissions to the Owner, the Group, and everyone else (Public). This is generally considered a security risk and should only be used when strictly necessary.

How to calculate chmod in unix?

Chmod is calculated by adding up numeric values: Read is 4, Write is 2, Execute is 1. You add these for each group (Owner, Group, Public). For example, Read (4) + Write (2) + Execute (1) = 7. If Owner gets 7, Group gets Read/Execute (5), and Public gets Read/Execute (5), the combined octal code is 755.