Chmod Calculator

Interactive Unix File Permissions Calculator

Select the appropriate permissions for Owner, Group, and Others to generate the correct numeric (octal) value, symbolic notation, and chmod command for Unix-like systems.

File Permissions

User Type Read (4) Write (2) Execute (1) Value
Owner 7
Group 5
Others 5

Quick Presets

Numeric (Octal) Value

755

Click to copy

Symbolic Notation

rwxr-xr-x

Unix permissions string

Command Example

chmod 755 filename

Replace 'filename' with your actual file or directory name

Permission Breakdown

Owner permissions: rwx (7)
Group permissions: r-x (5)
Others permissions: r-x (5)

Understanding Unix File Permissions

Read (4)

Permission to view the contents of the file or list directory contents.

Write (2)

Permission to modify the file contents or add/remove files in a directory.

Execute (1)

Permission to run the file as a program or access a directory.

How It Works

Each permission type (Owner, Group, Others) gets a number from 0-7 based on which permissions are granted. Read=4, Write=2, Execute=1. Add them together: Read+Write+Execute = 4+2+1 = 7. The final chmod value combines all three numbers (e.g., 755 = Owner:7, Group:5, Others:5).