chmod Permission Calculator
Convert numeric Unix file permissions to symbolic notation and build chmod modes interactively.
Calculate file permissions
Permission result
755 rwxr-xr-x
How Unix permission digits work
Read is worth 4, write is worth 2 and execute is worth 1. Each digit adds the permissions for owner, group and others. A leading digit may encode setuid, setgid and sticky bits, but this first version focuses on the three common permission digits.
Common chmod modes
644 is common for files, 755 for executable files and traversable directories, 700 for private executables or directories, and 600 for private data. 777 grants write permission to everyone and is rarely appropriate in production.
Frequently asked questions
What does chmod 755 mean?
The owner can read, write and execute; group and others can read and execute.
What does chmod 644 mean?
The owner can read and write; group and others can only read. It is common for non-executable files.
Why should chmod 777 usually be avoided?
It grants write access to everyone, which is rarely appropriate for production files or directories.