Question 1

What does the chmod calculator show?

Accepted Answer

Choose permission checkboxes or enter an octal number like 755 or a symbolic string like rwxr-xr-x. The calculator returns the octal value, the symbolic string, the file-listing form, and the ready-to-run chmod command. For example, 755 means rwxr-xr-x and the command chmod 755 filename.

Question 2

Which formula does the chmod calculator use?

Accepted Answer

Each class is read (4) plus write (2) plus execute (1). For example, rwx is 4 + 2 + 1 = 7, r-x is 4 + 0 + 1 = 5, and rwxr-xr-x is 755. A leading fourth digit covers the special bits: setuid (4), setgid (2), and sticky (1).

Question 3

Which inputs are accepted?

Accepted Answer

Tick permission checkboxes for owner, group, and other plus optional setuid, setgid, and sticky bits, or enter an octal permission with 3 or 4 digits from 0 to 7, or a 9-character symbolic string using r, w, x, s, t, and -. Empty values, invalid digits, and characters outside these sets show a clear error instead of a result.

Question 4

Do my values stay private?

Accepted Answer

Yes. The conversion and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.

Chmod Calculator for everyday work.