A buy-to-let mortgage calculator can give an initial estimate of your borrowing, monthly interest payments and potential rental yield. Enter the property price, deposit, mortgage rate and term, then compare the estimated rent with the mortgage payment and other costs, such as insurance, repairs, management fees and tax. Lenders may also assess the expected rental income using their own affordability tests, so calculator results are only indicative. Check current criteria with an FCA-authorised mortgage broker or lender before relying on the figures.