Free · England and Wales
Buy-to-let mortgage calculator
See the mortgage payment, whether the rent passes the lender's stress test, and what's left each month after every cost.
Questions
How much can I borrow for a buy-to-let?
Lenders size the loan on the rent, not your salary. Most want the rent to cover the mortgage interest 1.25 times at a 'stress' rate, often around 5.5%, and 1.45 times if you pay higher-rate tax. The full breakdown shows this check for your deal.
How big a deposit do I need?
Usually 25% of the price. Some lenders go to 80% or even 85% loan to value, at higher rates. On top of the deposit you need stamp duty or Land Transaction Tax, legal fees and the lender's fees.
Interest-only or repayment?
Most buy-to-let mortgages are interest-only: lower payments, but you still owe the whole loan at the end, usually cleared by selling or remortgaging. A repayment mortgage costs more each month and clears the loan.
Can I get tax relief on the mortgage interest?
If you own the property in your own name, you can't deduct the interest from the rent. Instead you get a tax credit of 20% of it (Section 24), rising to 22% from April 2027. A limited company deducts the interest in full.
More terms explained in the glossary.