# Rent vs Buy Calculator API

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

Year-by-year wealth comparison of renting and investing versus buying, with the breakeven year.

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

- Slug: `rent-vs-buy-calculator`
- Category: `finance`
- Version: `2026-04-22`
- Credits per successful call: 2
- Starts on: free
- Max payload: 65536 bytes
- Privacy mode: `hash_only`
- Available on: free, starter, pro, business, scale
- Browser tool: https://miniwebtool.com/rent-vs-buy-calculator/

## Endpoint

`POST https://api.miniwebtool.com/v1/tools/rent-vs-buy-calculator/run`

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `home_price` | `float` | no | purchase price |
| `down_payment_pct` | `float` | no | down payment % of price |
| `mortgage_rate` | `float` | no | annual mortgage rate % |
| `loan_term` | `str` | no | 30 | 20 | 15 Choices: 30, 20, 15 |
| `property_tax_rate` | `float` | no | annual property tax % of value |
| `home_insurance` | `float` | no | annual homeowners insurance |
| `hoa_fees` | `float` | no | monthly HOA fees |
| `maintenance_rate` | `float` | no | annual maintenance % of value |
| `closing_cost_pct` | `float` | no | closing costs % of price |
| `home_appreciation` | `float` | no | annual home appreciation % |
| `selling_cost_pct` | `float` | no | cost to sell % of value |
| `monthly_rent` | `float` | no | current monthly rent |
| `rent_increase` | `float` | no | annual rent increase % |
| `renters_insurance` | `float` | no | monthly renters insurance |
| `investment_return` | `float` | no | annual investment return % |
| `tax_bracket` | `float` | no | marginal tax bracket % |
| `time_horizon` | `int` | no | years to compare |

## Example request

```json
{
  "home_price": 400000,
  "down_payment_pct": 20,
  "mortgage_rate": 6.5,
  "loan_term": "30",
  "property_tax_rate": 1.1,
  "home_insurance": 1800,
  "hoa_fees": 0,
  "maintenance_rate": 1.0,
  "closing_cost_pct": 3.0,
  "home_appreciation": 3.0,
  "selling_cost_pct": 6.0,
  "monthly_rent": 2200,
  "rent_increase": 3.0,
  "renters_insurance": 15,
  "investment_return": 7.0,
  "tax_bracket": 22,
  "time_horizon": 10
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/rent-vs-buy-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"home_price":400000,"down_payment_pct":20,"mortgage_rate":6.5,"loan_term":"30","property_tax_rate":1.1,"home_insurance":1800,"hoa_fees":0,"maintenance_rate":1.0,"closing_cost_pct":3.0,"home_appreciation":3.0,"selling_cost_pct":6.0,"monthly_rent":2200,"rent_increase":3.0,"renters_insurance":15,"investment_return":7.0,"tax_bracket":22,"time_horizon":10}'
```

## Response envelope

```json
{
  "request_id": "01K...",
  "tool": "rent-vs-buy-calculator",
  "tool_version": "2026-04-22",
  "credits_used": 2,
  "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 Rent vs Buy Calculator API do?

Year-by-year wealth comparison of renting and investing versus buying, with the breakeven year. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.

### How much does one call cost?

2 credits 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.