What is it?
The chmod Calculator turns read, write and execute ticks into the chmod number (like 755), the letters (rwxr-xr-x) and the command, or decodes one you already have.
Who is it for?
Website owners on shared hosting, developers and Linux users setting safe permissions on files and folders.
How to use it
- Tick read, write and execute for owner, group and others, and choose File or folder.
- Or type in Number or letters: 3 digits from 0–7 (like 755) or 9 letters (like rwxr-xr-x).
- Pick from Common choices, then Copy the command.
Common choices
- 644 (rw-r--r--): web pages, images. 755 (rwxr-xr-x): folders and scripts.
- 600 (rw-------): private keys,
.envfiles and passwords. - 700: a private folder. 775/664: a shared team folder.
Avoid 777
777 (rwxrwxrwx) lets anyone on the server change the file. Hackers look for it. If a plugin “needs 777”, the real fix is usually the file owner, not the permission.
How the number works
Read = 4, write = 2, execute = 1, added up for each of owner, group and others: rwx = 7, r-x = 5, r-- = 4. On folders, “execute” means being allowed to open the folder.
Worked examples
chmod 644 index.html: owner can read and write; everyone else can only read. Right for web pages.chmod 755 uploads: the folder can be opened and listed by the web server.chmod 600 ~/.ssh/id_ed25519: SSH refuses keys that others can read, so private keys need 600.chmod -Rchanges a folder and everything inside: careful, it gives files and folders the same mode. Usefindto set files to 644 and folders to 755 separately.
Windows
chmod is for Linux, macOS and most web hosts. Windows uses a different permission system (right-click → Properties → Security). In cPanel File Manager, right-click a file → Change Permissions to tick the same boxes.
Errors and how to fix them
- “Type 3 digits from 0–7 (like 755) or 9 letters (like rwxr-xr-x).”: the number has a digit above 7 or the wrong length. Each digit is a sum of 4 (read), 2 (write) and 1 (run).
- The setting doesn’t work on my server: some hosts don’t allow certain permissions (for example 777). Use 755 for folders and 644 for files.
Open the tool: chmod Calculator
Still stuck?
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Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.