Unix Permissions Calculator

Claude Code: save as ~/.claude/skills/permissions-calculator/SKILL.md
claude.ai: Settings &rarr; Capabilities &rarr; Skills &rarr; upload the file

Enter either notation — octal (755) or symbolic (rwxr-xr-x) — and it converts automatically. Want to build a value from scratch instead? Try the CHMOD Builder.

ℹ️ How this works

Octal input can be 3 digits (755) or 4 with a leading special-bits digit (4755 for setuid). Symbolic input is 9 characters (rwxr-xr-x), optionally with a 10th leading file-type character (-, d, etc., as in ls -l output) which is ignored.
setuid/setgid show as s in the owner/group execute position (or S if execute isn't otherwise set); sticky shows as t in the other execute position (or T).
Runs entirely client-side on this page — nothing you type here is ever sent anywhere. The JSON API below is a separate, opt-in endpoint for scripts.

💻 Show API usage example (cURL)

curl -sS "https://devops.majbase.com/permissions-calculator/api?value=755"
curl -sS "https://devops.majbase.com/permissions-calculator/api?value=rwxr-xr-x"

Both return the same shape: {"mode": "octal"|"symbolic", "octal3": "755", "octal4": "0755", "symbolic": "rwxr-xr-x", "owner"/"group"/"other": {"value", "symbolic", "description"}, "special": {"setuid", "setgid", "sticky"}}.