Buy-to-let calculator
A guide, not financial advice
The purchase
Example numbers to start with: the £500,000 price is an example assumption, not market data (Close Knit, Oct 2026). Change any of them.
Average new fixed rates at 75% loan-to-value in Aug 2026: 4.92% for 2 years, 4.78% for 5 years (Bank of England, Aug 2026; tracker). Investor loans usually cost more.
Rent and running costs
The example rent (5.4% of the price a year), 2 empty weeks, a 12% agent fee, a 25% deposit and a 25-year term are an example assumption, not market data (Close Knit, Oct 2026): put in the real ones.
More costs
What it adds up to
- Gross yield
- 5.40%
- Net yield
- 4.57%85% of the gross yield kept after costs
- Cash flow a month
- £410
- Cash flow a year
- £4,921
- Cash needed
- £165,00033% of the price
- Yearly return on that cash
- 2.98%
| Rent if never empty | £27,000 |
|---|---|
| Rent after empty weeks | £25,962 |
| Running costs | -£3,115 |
| Mortgage payments | -£17,925 |
| Cash flow | £4,921 |
Loan £375,000 (75% of the price). Cash needed is the deposit, stamp duty of £40,000 (how it is worked out) and the fees you entered.
Left blank, so not counted — any of these lowers the return: service charge, ground rent, insurance, maintenance, legal and survey fees, refurbishment.
Figures are before income tax . Rents, rates and costs change; nothing here predicts them.