Chmod Calculator
Visual Unix file permission calculator. Toggle checkboxes or type an octal number to see permissions in both numeric and symbolic formats.
| Read | Write | Execute | Value | |
|---|---|---|---|---|
| Owner | 7 | |||
| Group | 5 | |||
| Others | 5 |
Common Presets
Permission Values
Read = 4, Write = 2, Execute = 1. Each digit in the octal number is the sum of its permissions. For example, 7 = 4+2+1 (rwx), 5 = 4+1 (r-x).
chmod Command
Use chmod 755 file to set permissions. The first digit is owner, second is group, third is others. Use -R flag for recursive.
How to Use the Chmod Calculator
- 1.Toggle the Read, Write, Execute checkboxes for Owner, Group, and Others to set permissions visually.
- 2.The octal number (e.g., 755) and symbolic notation (e.g., rwxr-xr-x) update in real time.
- 3.Alternatively, type a 3-digit octal number to see the corresponding checkboxes.
- 4.Use a preset for common configurations, then click Copy to use the value.
Frequently Asked Questions
What does chmod 755 mean?
chmod 755 gives the owner full permissions (read, write, execute) and gives group and others read and execute permissions. This is the standard for directories and executable scripts.
What is the difference between 644 and 755?
644 gives the owner read/write and everyone else read-only — ideal for files. 755 adds execute permission for everyone — needed for directories and scripts to be accessible.
What does the execute permission do on a directory?
On a directory, execute (x) means the ability to traverse (cd into) the directory and access files within it. Without execute on a directory, you cannot list or access its contents even with read permission.
Should I ever use chmod 777?
chmod 777 gives full read, write, and execute permission to everyone, including other users on the system. This is a security risk and should be avoided in production. Use the most restrictive permissions that still allow your application to work.