chmod Calculator
Free online chmod calculator. Convert Unix file permissions between numeric (755), symbolic (rwxr-xr-x) and human-readable formats. Interactive permission toggle for Owner, Group and Others.
| Owner | Group | Others |
|---|
How to Use chmod Calculator
Toggle Permissions
Check or uncheck the Read, Write, and Execute boxes for Owner, Group, and Others. The numeric and symbolic values update in real-time as you change permissions.
Read the chmod Value
The numeric (octal) chmod value appears at the top — e.g., 755 or 644. The symbolic form is shown below — e.g., rwxr-xr-x. Both represent the same permission set.
Copy and Use
Copy the chmod command and paste it into your terminal: chmod 755 script.sh. The tool shows you exactly which permissions each digit represents.
Common chmod Values
| chmod | Symbolic | Use Case |
|---|---|---|
| 777 | rwxrwxrwx | Everyone can do everything — avoid |
| 755 | rwxr-xr-x | Directories and executable scripts |
| 644 | rw-r--r-- | Standard file permissions |
| 600 | rw------- | Private files (SSH keys, configs) |
Frequently Asked Questions
What do chmod numbers mean?
Each digit represents permissions for Owner, Group, and Others respectively. Each digit is the sum of: read=4, write=2, execute=1. So 7 = 4+2+1 = rwx (full access), 5 = 4+1 = r-x (read and execute), 6 = 4+2 = rw- (read and write), 4 = r-- (read only), 0 = --- (no access). chmod 755 means: owner gets rwx, group gets r-x, others get r-x.
What are common chmod values?
644 (rw-r--r--): standard for files — owner can read/write, everyone else can read. 755 (rwxr-xr-x): standard for directories and executables — owner has full access, others can read and execute. 600 (rw-------): private files — only owner can read/write. 777 (rwxrwxrwx): everyone has full access — security risk, almost never use this. 700 (rwx------): private scripts — only owner can access.
How do I set permissions recursively?
Add the -R flag: chmod -R 755 directory/. This applies the permission to the directory and everything inside it — all files and subdirectories. Be careful with -R on existing directories — it can change permissions on files that were deliberately set differently. For new deployments, set directory permissions first, then file permissions separately.