Unix permission converter
Convert Unix permissions between octal and symbolic form, like 755 and rwxr-xr-x, including setuid, setgid and sticky bits; chmod is never run.
- Runs in your browser
- No upload
- Instant result
Assumptions & formula
Formula and assumptions
r=4 w=2 x=1; setuid=4 setgid=2 sticky=1; s/S t/T
Results
Enter values and press Calculate to see the result here.
How to use this calculator
- Set inputs and units
Choose octal or symbolic mode. Enter three or four octal digits, or the nine permission characters without the file-type prefix.
- Calculate
Check this worked example: 4755 → rwsr-xr-x; 644 → rw-r--r--
- Results
Check the owner, group, others and special bits before you copy. Broader permissions are not automatically safer.
Questions and limits
What is the difference between s and S?
Both indicate set-ID. The lowercase one also has execute permission, and the uppercase one doesn't. t and T make the same distinction for execution with the sticky bit.
Which input errors should I correct?
Octal digits are 0–7. Symbolic text must keep each r/w/x position, using - for permissions that are absent.
What does this calculation leave out?
Conversion only. It makes no filesystem changes and doesn't handle ACLs, ownership or umask, or predict platform-specific execution rules.