# Decking Calculator API

> For the complete documentation index, see [llms.txt](/llms.txt).

Estimate decking boards, joists, beams, posts, fasteners, and waste.

Use this endpoint to add the tool to your app, site, workflow, or agent without rebuilding formulas, validation, examples, and docs.

- Slug: `decking-calculator`
- Category: `construction`
- Version: `2026-04-22`
- Credits per successful call: 1
- Starts on: free
- Max payload: 65536 bytes
- Privacy mode: `hash_only`
- Available on: free, starter, pro, business, scale
- Browser tool: https://miniwebtool.com/decking-calculator/

## Endpoint

`POST https://api.miniwebtool.com/v1/tools/decking-calculator/run`

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `unit_system` | `str` | no | customary | metric Choices: customary, metric |
| `deck_length` | `float` | no |  |
| `deck_width` | `float` | no |  |
| `board_width` | `float` | no |  |
| `board_length` | `float` | no |  |
| `board_gap` | `float` | no |  |
| `joist_spacing` | `float` | no |  |
| `beam_spacing` | `float` | no |  |
| `waste_factor` | `float` | no |  |
| `fasteners_per_sqft` | `float` | no |  |
| `precision` | `int` | no |  |

## Example request

```json
{
  "unit_system": "customary",
  "deck_length": 12,
  "deck_width": 10,
  "board_width": 5.5,
  "board_length": 12,
  "board_gap": 0.125,
  "joist_spacing": 16,
  "beam_spacing": 8,
  "waste_factor": 10,
  "fasteners_per_sqft": 3.5,
  "precision": 2
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/decking-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"unit_system":"customary","deck_length":12,"deck_width":10,"board_width":5.5,"board_length":12,"board_gap":0.125,"joist_spacing":16,"beam_spacing":8,"waste_factor":10,"fasteners_per_sqft":3.5,"precision":2}'
```

## Response envelope

```json
{
  "request_id": "01K...",
  "tool": "decking-calculator",
  "tool_version": "2026-04-22",
  "credits_used": 1,
  "result": {}
}
```

## Errors

Errors are RFC 7807 `application/problem+json`. Branch on `code`, not `title`.

## MCP

Agents can discover and call this tool through `https://api.miniwebtool.com/mcp` or `https://api.miniwebtool.com/v1/mcp` using MCP `tools/list` and `tools/call`.

## Frequently asked

### What does the Decking Calculator API do?

Estimate decking boards, joists, beams, posts, fasteners, and waste. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.

### How much does one call cost?

1 credit per successful call. Failed calls do not bill.

### What parameters are required?

Required fields: (none). Full schema at `https://api.miniwebtool.com/v1/openapi.json`.

### Is this deterministic?

Yes. Same input, same output. Tool version: 2026-04-22.