# Rental Yield Calculator

> Annualizes a weekly, monthly or annual rent and computes the gross rental yield on the property value and the net yield after annual expenses and purchase costs, plus the monthly net income.

- Calculator id: `rental-yield` · Category: Investing & Real Estate (`investing`) · Tool name: `calculate_rental_yield`
- Canonical page: https://tttkmbb.com/investing/rental-yield · This document: https://tttkmbb.com/investing/rental-yield.md · JSON definition: https://tttkmbb.com/investing/rental-yield.json

## Purpose

Annualizes a weekly, monthly or annual rent and computes the gross rental yield on the property value and the net yield after annual expenses and purchase costs, plus the monthly net income.

**Use when:** You want the yield of a buy-to-let or investment property from its rent and value, in the gross form quoted by agents or the net form after costs.

**Do not use when:** You need the return on the cash invested with a mortgage (use cash-on-cash-return) or a commercial-style NOI cap rate with vacancy (use cap-rate). Informational only; not financial advice.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `property_value` | number |  | required | Purchase price or current market value. (> 0, max 1000000000000) |
| `rent_amount` | number |  | required | Rent charged per rent_period. (min 0, max 10000000000) |
| `rent_period` | enum: weekly \| monthly \| annual |  | optional, default "monthly" | Period of rent_amount; weekly rent is annualized with 52 weeks. |
| `annual_expenses` | number |  | optional, default 0 | Yearly owner costs: management fees, insurance, maintenance, rates, vacancy allowance (excluding mortgage interest). (min 0, max 1000000000000) |
| `purchase_costs` | number |  | optional, default 0 | One-off acquisition costs (stamp duty, legal fees) added to the value for the net yield. (min 0, max 1000000000000) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `annual_rent` | number |  | rent_amount × 52, × 12 or × 1. |
| `monthly_rent` | number |  | annual_rent / 12. |
| `gross_yield_percent` | number | % | annual_rent / property_value × 100. |
| `net_yield_percent` | number | % | (annual_rent − annual_expenses) / (property_value + purchase_costs) × 100. |
| `annual_net_income` | number |  | annual_rent − annual_expenses. |
| `monthly_net_income` | number |  | annual_net_income / 12. |

## Formula

`annual_rent = rent_amount × {weekly: 52, monthly: 12, annual: 1}; gross_yield_percent = annual_rent / property_value × 100; net_yield_percent = (annual_rent − annual_expenses) / (property_value + purchase_costs) × 100`

Gross yield is the figure usually quoted in listings; net yield deducts running costs and spreads purchase costs over the value. Neither includes mortgage costs, tax or capital growth. Informational mathematics only; not financial advice.

## Data Sources

- Wikipedia – Buy to let (rental yield) — https://en.wikipedia.org/wiki/Buy_to_let (reference, retrieved 2026-09-24)
- Wikipedia – Capitalization rate — https://en.wikipedia.org/wiki/Capitalization_rate (reference, retrieved 2026-09-24)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/rental-yield?property_value=…&rent_amount=…`
- `POST https://tttkmbb.com/api/v1/calculate/rental-yield` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/rental-yield · OpenAPI operationId `calculate_rental_yield` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "rental-yield", "inputs": {…}}`

## Example

- 500,000 value, 500 per week: inputs `{"property_value":500000,"rent_amount":500,"rent_period":"weekly"}` → `{"annual_rent":26000,"monthly_rent":2166.67,"gross_yield_percent":5.2,"net_yield_percent":5.2,"monthly_net_income":2166.67}`
- 400,000 value, 2,000 per month, 6,000 expenses, 20,000 purchase costs: inputs `{"property_value":400000,"rent_amount":2000,"rent_period":"monthly","annual_expenses":6000,"purchase_costs":20000}` → `{"annual_rent":24000,"gross_yield_percent":6,"net_yield_percent":4.29,"annual_net_income":18000,"monthly_net_income":1500}`

```
GET https://tttkmbb.com/api/v1/calculate/rental-yield?property_value=500000&rent_amount=500&rent_period=weekly
```

## Limitations

You need the return on the cash invested with a mortgage (use cash-on-cash-return) or a commercial-style NOI cap rate with vacancy (use cap-rate). Informational only; not financial advice. Gross yield is the figure usually quoted in listings; net yield deducts running costs and spreads purchase costs over the value. Neither includes mortgage costs, tax or capital growth. Informational mathematics only; not financial advice. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Why 52 weeks and not 52.14?**

52 weeks is the convention used by most agents and lenders; multiplying by 365/7 instead would raise the annual rent by about 0.3 %.

**What counts as a good rental yield?**

It depends on the market and interest rates; a net yield should be compared with the mortgage rate and alternative investments, and gross yields of 3–8 % are typical in many housing markets.

## Related

- [Cap Rate Calculator](https://tttkmbb.com/investing/cap-rate.md) — NOI-based yield with vacancy and expenses.
- [Gross Rent Multiplier Calculator](https://tttkmbb.com/investing/gross-rent-multiplier.md) — Price divided by annual rent.
- [Mortgage Payment Calculator](https://tttkmbb.com/finance/mortgage-payment.md) — Mortgage cost to compare against the net income.