Convert Unix/Linux file permissions between symbolic (rwx) and numeric (octal) formats. Generate chmod commands instantly.
ls -lchmod 644 filename3 digits, each 0-7 (e.g., 644, 755, 777)
9 characters using r, w, x, - (e.g., rw-r--r--)
Select permissions
Check the boxes for read, write, and execute permissions for owner, group, and others.
View the results
See the octal (numeric) and symbolic (rwx) representations update in real-time.
Copy the command
Copy the generated chmod command to use in your terminal.
Yes, our Chmod Calculator is completely free to use with no limitations. Convert between symbolic and octal permissions as many times as you need without any sign-ups or restrictions.
Absolutely. All permission calculations happen entirely in your browser using JavaScript. No data is ever sent to any server. This client-side approach ensures complete privacy.
chmod (change mode) is a Unix/Linux command that changes file and directory permissions. You use it to control who can read, write, or execute files. For example, 'chmod 755 script.sh' makes a script executable by everyone but writable only by the owner.
Each digit represents permissions for owner, group, and others. The values are: 4 (read), 2 (write), 1 (execute). Add them together: 7 = rwx (full access), 6 = rw- (read/write), 5 = r-x (read/execute), 4 = r-- (read only), 0 = --- (no access).
755 is most common for directories and scripts (owner full access, others read/execute). 644 is standard for files (owner read/write, others read only). 700 is for private directories. 600 is for sensitive files like SSH keys. Never use 777 in production.