Chmod Calculator
Calculate visual Linux file permissions and translate between octal and symbolic formats.
Linux file permissions
chmod controls who can read, write, or execute a file. This calculator keeps the checkboxes, octal value, and symbolic value in sync so you can see what a permission string such as 755 actually means.
The three columns map to owner, group, and everyone else. Each permission has a number: read is 4, write is 2, and execute is 1.
Reading octal values
- 7: read, write, and execute
- 6: read and write
- 5: read and execute
- 4: read only
- 0: no permissions
Examples
- 755: common for scripts and directories that others can enter
- 644: common for regular files that others can read
- 600: common for private config files and keys
- 777: full access for everyone; usually a sign to stop and review
How to use Chmod Calculator
The chmod calculator converts Linux file permissions between checkboxes, symbolic permissions, and octal numbers. It helps avoid guessing values like 755 or 644.
Developers often use this page when they need online chmod calculator, chmod calculator, chmod 755 calculator, and linux permission calculator.
Privacy and data handling
This tool is designed to run in your browser for normal use, so your input does not need to be sent to a server.
- Input and output stay on the page while you work.
- Copy buttons use your browser clipboard permission when available.
- Avoid pasting private production data on shared or untrusted devices.
Examples
Read chmod 755
Input
755Output
owner: read write execute
group: read execute
others: read executeThis is common for directories and executable scripts.
Steps
- 1Choose read, write, and execute permissions for owner, group, and others.
- 2Review the octal and symbolic output.
- 3Use the value in a chmod command if it matches your intent.
Common use cases
- Set executable permission on a script.
- Check common web file permissions.
- Understand what a permission number means.
Practical tips
- Use 755 for many executable scripts and directories.
- Use 644 for many regular files.
- Be careful with 777 because it gives everyone full access.
FAQ
What does chmod 755 mean?
It means the owner can read, write, and execute. Group and others can read and execute.
What does chmod 777 mean?
It gives read, write, and execute permissions to everyone. It is usually too open for real systems.