A mortgage calculator for buy-to-let can estimate monthly repayments using the property price, deposit, loan term, interest rate and repayment type. Many buy-to-let lenders also assess whether the expected rent covers their affordability stress test, so enter a realistic rental figure where the calculator allows it. Remember to budget for arrangement fees, valuation costs, insurance, maintenance, void periods and possible tax, which basic calculators may not include. The result is only an illustration; an FCA-authorised mortgage adviser or lender can confirm what you may be able to borrow based on your circumstances.