Buy to Let Mortgage Repayment Calculator
Use this buy to let mortgage repayment calculator to compare a repayment mortgage with an interest-only mortgage on the same loan. Repayment costs more each month but clears the debt; interest-only costs less each month but leaves the full loan to repay at the end.
Calculator
How to use this calculator
- Enter the loan amount, interest rate and term.
- Choose repayment or interest-only, then click Calculate.
- Compare the monthly payment, the total paid and the balance left at the end of the term.
Worked example: a £180,000 loan at 5.5% over 25 years costs about £1,105 per month on repayment, with about £151,600 of total interest and a zero balance at the end. Interest-only costs about £825 per month, with about £247,500 of total interest and the full £180,000 still to repay.
Frequently Asked Questions
How are buy to let mortgage repayments calculated?
A repayment payment uses the standard amortisation formula: the loan, the monthly rate and the number of months together produce a fixed payment that clears the loan by the end of the term, assuming the rate never changes.
Is repayment or interest only better for buy to let?
It depends on your goal. Repayment builds equity and removes refinancing risk, but lowers monthly cash flow. Interest only maximises cash flow but leaves the debt in place.
Does the rate stay fixed for the whole term?
Usually not. Most deals fix the rate for 2 to 5 years, then move to a variable rate. This calculator assumes one rate for the whole term, so treat long-term totals as illustrations.
Can I switch between repayment and interest only later?
Often yes, at remortgage or by agreement with the lender, but the lender will reassess affordability and the property at that point.