How to use the Chmod Calculator
- Tick read, write and execute for owner, group and others.
- Or type a numeric mode such as 644.
- Copy the chmod command.
What does this tool do?
Each permission has a value: read = 4, write = 2, execute = 1. Adding them gives one digit per class of user — owner, group, others. So rwx (4+2+1) is 7 and r-x (4+1) is 5, making rwxr-xr-x equal to 755.
Why use it?
- Set safe permissions on web servers.
- Understand error messages about permissions.
- No more mental arithmetic.
Common modes
Typical permissions:
| Mode | Symbolic | Typical use |
|---|---|---|
| 644 | rw-r--r-- | Normal files |
| 755 | rwxr-xr-x | Folders and scripts |
| 600 | rw------- | Private keys, secrets |
| 700 | rwx------ | Private folders |
| 777 | rwxrwxrwx | Avoid — anyone can modify |
Privacy
Everything you type is processed in your browser. Nothing you enter is sent to our servers or stored by us. There's no account to create and nothing to install.
Last reviewed by the M2Toolkit team.