Skip to content

chmod Calculator

Convert Unix permissions between numeric modes like 755 and symbolic rwx notation with a checkbox grid, setuid, setgid and sticky bits, and presets.

chmod Calculator

RoleReadWriteExecute
owner
group
other
Numeric
644
Symbolic
rw-r--r--

Updated . Provided as is. Check the output before you rely on it in production.

How to use chmod Calculator

  1. 1

    Start from a preset or type numeric mode

    Pick a common preset such as 644 or 755, or type a numeric mode directly in the input. The grid updates as soon as the mode is valid.

  2. 2

    Adjust Owner/Group/Other checkboxes

    Toggle Read, Write, and Execute checkboxes for each role. Numeric mode and symbolic permissions update instantly from checkbox changes.

  3. 3

    Use bidirectional conversion

    Edit numeric mode to drive the grid, or edit the grid to drive numeric mode. This helps verify permissions before running chmod in a terminal.

  4. 4

    Copy numeric, symbolic, or both

    Copy each format individually or copy both formats together for docs, shell commands, and permission reviews.

Questions and answers

How does the numeric chmod value map to rwx?
Each digit is read, write, execute as 4, 2, 1. For example, 7 means rwx, 5 means r-x, and 4 means r--.
Can I edit permissions both ways?
Yes. Typing a numeric mode updates the checkbox grid, and toggling checkboxes updates the numeric mode instantly.
Which chmod presets are included?
The calculator includes common presets: 644, 755, 777, 600, 700, and 400.
Can I copy numeric and symbolic results?
Yes. You can copy numeric mode, symbolic mode, or both formats together for terminal usage and documentation.

Use it as an API

chmod Calculator is also callable as a free HTTP JSON API at https://aidevhub.io/api/chmod-calculator/ — GET with query parameters or POST with a JSON body, no authentication, CORS enabled, fair use (abusive traffic is throttled at the edge; there is no per-request quota header). Responses return { ok, tool, result, meta }. 

curl -s "https://aidevhub.io/api/chmod-calculator/?mode=755"

Machine-readable contract: /api/tool/chmod-calculator.json All API endpoints: /agents/ LLM site index: /llms.txt

For AI agents: how to call this tool

Machine-readable contract, endpoints and examples. Humans can ignore this section.

Best Path For Builders

Dedicated API endpoint

Deterministic outputs, machine-safe contracts, and production-ready examples.

Dedicated API

https://aidevhub.io/api/chmod-calculator/

OpenAPI: https://aidevhub.io/api/openapi.yaml

GET /api/chmod-calculator/ GET chmod-calculator
POST /api/chmod-calculator/ POST chmod-calculator