Owner, group, and public
The first digit controls the file owner, the second digit controls the assigned group, and the third digit controls everyone else on the system.
Linux Permission Console
Chmod Calculator
Use this chmod calculator to convert Linux read, write, and execute permissions into octal codes, symbolic rwx notation, and copy-ready terminal commands.
Octal
755
Symbolic
rwxr-xr-x
Permission Matrix
Owner, Group, and Public each combine Read, Write, and Execute.
Owner
User account that owns the file.
7
Group
Users that belong to the file group.
5
Public
Everyone else on the system.
5
Linux chmod permissions reference
Linux file permissions are controlled separately for the owner, group, and public. Each permission has a numeric value: read is 4, write is 2, and execute is 1. Add the selected values in each column to build a chmod code such as 755, 644, or 700.
Octal to rwx notation
A permission like 755 becomes rwxr-xr-x: the owner has full access, while group and public users can read and execute.
Safer default choices
Common defaults include 755 for folders and executable scripts, 644 for public files, and 700 for private folders.
What is a chmod calculator?
A chmod calculator converts Linux permission choices into octal codes, symbolic rwx notation, and terminal commands.
What does chmod 755 mean?
chmod 755 means the owner can read, write, and execute, while group and public users can read and execute but cannot write.
Is chmod 777 safe?
chmod 777 is usually unsafe because it gives everyone read, write, and execute access. Avoid it on shared or public systems.
How do I use the chmod command?
Pick the permissions you need, copy the generated command, then run it in a terminal for the target file or folder.