# Percentage Calculator — REST API endpoint `percentage`

Calculate percentages: X% of Y, percent change, increase, or decrease.

- Category: conversion
- REST endpoint: POST https://api.findutils.com/api/tools/percentage/execute (no API keys, 60 req/min per IP)
- MCP: not exposed on the MCP server. See https://findutils.com/mcp/ for the tools that are.
- Reference page: https://findutils.com/api/percentage/

## Call the endpoint (verified example)

```bash
curl -X POST https://api.findutils.com/api/tools/percentage/execute \
  -H "Content-Type: application/json" \
  -d '{
    "mode": "of",
    "x": 15,
    "y": 200
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/percentage
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `mode` | string (of \| change \| increase \| decrease \| what_percent) | yes |  |
| `x` | number | yes | First number (see mode description). |
| `y` | number | yes | Second number (see mode description). |

Example arguments (verified):

```json
{
  "mode": "of",
  "x": 15,
  "y": 200
}
```

OpenAPI 3.1 spec: https://findutils.com/api/openapi.json · Interactive docs: https://findutils.com/api/docs/

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Full catalog: GET https://api.findutils.com/api/tools · https://findutils.com/api/ · https://findutils.com/llms.txt