chmod Calculator
Calculate Unix and Linux file permissions using octal and symbolic notation.
Permission Matrix
| Role | Read (r) | Write (w) | Execute (x) | Octal |
|---|---|---|---|---|
| Owner | 6 | |||
| Group | 4 | |||
| Others | 4 |
Special Bits
chmod command
chmod 644 <file>Symbolic
rw-r--r--Octal input
3-digit: 644
4-digit: 0644
Common Permission Reference
rw-r--r--Regular file (owner writes, others read)rwxr-xr-xExecutable / directory (owner full, others execute)rw-------Private file (owner read/write only)rwxrwxrwxWorld-writable (not recommended in production)r--------Read-only (commonly used for key files)rwsr-xr-xsetuid executable (e.g. /usr/bin/sudo)rwxrwxrwtSticky directory (e.g. /tmp — anyone can write, nobody can delete others' files)Related Tools
What does chmod Calculator do?
Calculate Unix and Linux file permissions using octal and symbolic notation. Review owner, group, other-user access and special bits before applying chmod settings.
Interpreting results and common questions
Does the calculator modify server permissions?
No. It calculates notation without running chmod. Check ownership, groups, directory execute permissions and special bits before applying a result.
References and result limitations
Local results depend on the input and selected options. Retain the input example, format and processing rules when citing a result, and verify the output. Keep keys and other sensitive material out of public examples.
These references explain protocol or format rules; they do not endorse results produced by this site.