# Roi Calculator — MCP tool `findutils:roi_calculator`

Return the return on investment: total invested (amount plus extra costs), net gain, simple ROI percent, annualized ROI percent, years to double at that rate (rule of 72), gain per year, and the percentage gain on the base amount alone.

- Category: finance
- MCP server: https://mcp.findutils.com/ (Streamable HTTP, no API keys, 120 req/min per IP)
- REST endpoint: POST https://api.findutils.com/api/tools/roi-calculator/execute (no API keys, 60 req/min per IP)
- Reference page: https://findutils.com/mcp/roi-calculator/
- Same tool on the other surface: https://findutils.com/api/roi-calculator/

## Connect

```bash
claude mcp add findutils --transport http https://mcp.findutils.com/
```

Claude Desktop (`claude_desktop_config.json`):

```json
{
  "mcpServers": {
    "findutils": {
      "url": "https://mcp.findutils.com/"
    }
  }
}
```

## Call the tool (verified example)

```bash
curl -X POST https://mcp.findutils.com/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/call",
    "params": {
      "name": "roi_calculator",
      "arguments": {
        "investment_amount": 10000,
        "final_value": 15000,
        "investment_years": 3,
        "additional_costs": 0
      }
    }
  }'
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `investment_amount` | number | yes | Amount invested. Must be > 0. |
| `final_value` | number | yes | Value of the investment at the end. |
| `investment_years` | number | no | Holding period in years. Must be > 0. Default: 1. |
| `additional_costs` | number | no | Fees, taxes, or other costs added to the investment. Default: 0. |

Example arguments (verified):

```json
{
  "investment_amount": 10000,
  "final_value": 15000,
  "investment_years": 3,
  "additional_costs": 0
}
```

## Also a REST endpoint

```bash
curl -X POST https://api.findutils.com/api/tools/roi-calculator/execute \
  -H "Content-Type: application/json" \
  -d '{
    "investment_amount": 10000,
    "final_value": 15000,
    "investment_years": 3,
    "additional_costs": 0
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/roi-calculator
```

Full REST reference: https://findutils.com/api/roi-calculator/ · OpenAPI 3.1 spec: https://findutils.com/api/openapi.json

---
Full catalog: POST https://mcp.findutils.com/ with method `tools/list` · https://findutils.com/mcp/ · https://findutils.com/llms.txt