Chmod Calculator — Convert Numeric & Symbolic Permissions
| Read | Write | Execute | |
|---|---|---|---|
| Owner (user) | |||
| Group | |||
| Others |
Symbolic
rwxr-xr-x
ls -l
-rwxr-xr-x Command
chmod 755 file
What this allows
Tick the read, write, and execute boxes for owner, group, and others — or type a numeric mode like 755 — and this chmod calculator shows the matching symbolic string, the ls -l line, the exact chmod command, and what each permission actually allows. It handles the setuid, setgid, and sticky bits too, and runs entirely in your browser.
How it works
- 1 Type a numeric mode or tick the boxes Enter a value like 755 or 0644 in the mode field, or check the read/write/execute boxes for owner, group, and others. Both stay in sync.
- 2 Read the symbolic output The tool shows the nine-character symbolic form (rwxr-xr-x), the full ls -l line, and the chmod command ready to copy.
- 3 Check the plain-English breakdown Each line explains who can do what, including any special bits, so you can confirm the permissions before applying them.
Your data stays private
All processing happens entirely in your browser. No files, text, or data are ever sent to our servers. You can disconnect from the internet and this tool will still work.
Frequently asked questions
- What does chmod 755 mean?
- The owner can read, write, and execute (7 = 4+2+1); the group can read and execute (5 = 4+1); others can read and execute (5). In symbolic form that is rwxr-xr-x — a common mode for scripts and directories.
- How do the numbers map to permissions?
- Each digit is a sum: read is 4, write is 2, execute is 1. Add the ones you want. 6 means read + write, 5 means read + execute, 7 means all three, and 0 means no access.
- What is the fourth (leading) digit for?
- It sets the special bits: 4 is setuid, 2 is setgid, and 1 is the sticky bit. So 4755 adds setuid to 755. Leave it off (or 0) when you don't need special bits.
- What do setuid, setgid, and the sticky bit do?
- Setuid runs an executable with the file owner's user ID. Setgid runs it with the group's ID and makes new files in a directory inherit that group. The sticky bit on a directory (like /tmp) lets only a file's owner delete or rename it.
- What's the difference between chmod 644 and 755?
- 644 (rw-r--r--) is typical for regular files: the owner can edit, everyone else can only read. 755 (rwxr-xr-x) adds the execute bit, which you need for scripts, programs, and directories you want to enter.
- Does this send my input anywhere?
- No. The calculation runs entirely in your browser with JavaScript. Nothing you type is uploaded, logged, or stored.
From the blog
chmod Explained: Reading and Writing Unix File Permissions How the numeric and symbolic permission formats work, what 755 and 644 mean, and when to use setuid, setgid, and the sticky bit. Read the post →Related tools
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