# Z-Score Calculator API

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

Calculate z-scores, inverse values, percentiles, and normal probabilities.

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

- Slug: `zscore-calculator`
- Category: `math`
- 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/zscore-calculator/

## Endpoint

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

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `calc_mode` | `str` | no | value_to_z | z_to_value Choices: value_to_z, z_to_value |
| `data_value` | `float` | no |  |
| `zscore_input` | `float` | no |  |
| `mean` | `float` | no |  |
| `std_dev` | `float` | no |  |
| `precision` | `int` | no |  |

## Example request

```json
{
  "calc_mode": "value_to_z",
  "data_value": 85,
  "mean": 75,
  "std_dev": 10,
  "precision": 4
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/zscore-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"calc_mode":"value_to_z","data_value":85,"mean":75,"std_dev":10,"precision":4}'
```

## Response envelope

```json
{
  "request_id": "01K...",
  "tool": "zscore-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 Z-Score Calculator API do?

Calculate z-scores, inverse values, percentiles, and normal probabilities. 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.