# Concrete Calculator API

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

Concrete volume in cubic feet/yards/meters plus pre-mix bag counts for slabs, footings, round columns, and staircases.

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

- Slug: `concrete-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/concrete-calculator/

## Endpoint

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

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `project_type` | `str` | no | slab | footing | column | stairs Choices: slab, footing, column, stairs |
| `unit_system` | `str` | no | imperial | metric Choices: imperial, metric |
| `length` | `float` | no | length, or tread run for stairs |
| `width` | `float` | no | width, or stair width for stairs |
| `thickness` | `float` | no | thickness/depth, or riser height for stairs |
| `diameter` | `float` | no | column diameter (column projects only) |
| `column_count` | `int` | no |  |
| `step_count` | `int` | no |  |
| `waste_pct` | `float` | no |  |

## Example request

```json
{
  "project_type": "slab",
  "unit_system": "imperial",
  "length": 12,
  "width": 10,
  "thickness": 4,
  "waste_pct": 10
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/concrete-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"project_type":"slab","unit_system":"imperial","length":12,"width":10,"thickness":4,"waste_pct":10}'
```

## Response envelope

```json
{
  "request_id": "01K...",
  "tool": "concrete-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 Concrete Calculator API do?

Concrete volume in cubic feet/yards/meters plus pre-mix bag counts for slabs, footings, round columns, and staircases. 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.