# Yarn Calculator API

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

Estimate yarn yards, meters, grams, and skeins for common knitting/crochet projects.

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

- Slug: `yarn-calculator`
- Category: `lifestyle`
- 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/yarn-calculator/

## Endpoint

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

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `project_type` | `str` | no | sweater_m | cardigan_m | baby_blanket | throw_blanket | queen_blanket | scarf | hat_adult | mittens | socks_crew | pillow_18 | dishcloth | market_bag | custom Choices: sweater_m, cardigan_m, baby_blanket, throw_blanket, queen_blanket, scarf, hat_adult, mittens, socks_crew, pillow_18, dishcloth, market_bag, custom |
| `yarn_weight` | `str` | no | lace | super_fine | fine | light | medium | bulky | super_bulky | jumbo Choices: lace, super_fine, fine, light, medium, bulky, super_bulky, jumbo |
| `stitch_pattern` | `str` | no | stockinette | ribbing | cables | lace | colorwork | textured | brioche Choices: stockinette, ribbing, cables, lace, colorwork, textured, brioche |
| `custom_yards` | `float | None` | no |  |
| `gauge_sts` | `float | None` | no |  |
| `skein_yards` | `float | None` | no |  |

## Example request

```json
{
  "project_type": "sweater_m",
  "yarn_weight": "medium",
  "stitch_pattern": "stockinette",
  "skein_yards": 200
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/yarn-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"project_type":"sweater_m","yarn_weight":"medium","stitch_pattern":"stockinette","skein_yards":200}'
```

## Response envelope

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

Estimate yarn yards, meters, grams, and skeins for common knitting/crochet projects. 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.