CHMOD Permission Calculator
Build Unix/Linux file permission octals by selecting read, write, and execute rights for owner, group, and others.
Results
What is it?
Unix/Linux file permissions control who can read, write, or execute a file. They are represented as a 3-digit octal number, one digit each for the owner, group, and all others. Each digit is the sum of: Read (4) + Write (2) + Execute (1).
How to use
Toggle the read, write, and execute switches for Owner, Group, and Others. The calculator sums each group values (r=4, w=2, x=1) into an octal digit, then assembles the three digits into the final chmod value you can use directly in a terminal.
Example scenario
A web server config file should be readable and writable by owner (rw- = 6), readable by group (r-- = 4), readable by others (r-- = 4): chmod 644. An executable script for the owner only (rwx = 7), no access for others (--- = 0): chmod 700.
Pro tip
Common permission values: 755 (rwxr-xr-x) — owner full, others read+execute, typical for directories and executables. 644 (rw-r--r--) — owner read+write, others read-only, typical for config files. 777 (rwxrwxrwx) — all permissions for everyone — NEVER use on a production server; it is a major security vulnerability. Use "ls -la" in a terminal to view current permissions.