Unix chmod calculator
Convert between octal and symbolic Unix permissions, including setuid, setgid and sticky bits.
A clear answer. Here’s how.
The three permission digits are sums of read (4), write (2) and execute (1) for owner, group and others. An optional leading digit adds setuid (4), setgid (2) and sticky (1). In symbolic form s or t means the special bit with execute set, and S or T means the special bit without execute. A umask removes bits from the default of 666 for files and 777 for directories. This explains modes only; it does not change any file.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Octal or symbolic mode
- 755
- Optional umask
- 022
Example result
- Octal mode
- 0755
- Symbolic mode
- rwxr-xr-x
- chmod command
- chmod 755 path
- Owner (user)
- read, write, execute
- Group
- read, execute
- Others
- read, execute
- Special bits
- None
- ls -l (file)
- -rwxr-xr-x
- ls -l (directory)
- drwxr-xr-x
- New file with umask 022
- 0644 (rw-r--r--)
- New directory with umask 022
- 0755 (rwxr-xr-x)
Permissions are Unix file modes. Read and write apply to the file contents; execute on a directory means permission to enter it. setuid, setgid and sticky bits behave differently across file systems and are ignored on many scripts.