Mortgage Calculator UK: monthly repayments
Enter the property price, your deposit, the interest rate and the term to see your monthly repayment, total interest and how much overpaying could save.
Estimates for information only, using 2026/27 rates for England, Wales and Northern Ireland unless stated. Not financial or tax advice; check your own situation with HMRC or a qualified adviser.
How it works
A repayment mortgage pays off interest and some of the loan each month, so the balance falls to zero by the end of the term. Interest-only mortgages pay just the interest, and the full loan is still owed at the end.
Monthly repayment = loan Γ r Γ· (1 β (1 + r)^βn), where r is the monthly interest rate and n is the number of months.
Overpaying reduces the balance sooner, so less interest builds up. Most fixed deals let you overpay up to 10% a year without a charge.
Frequently asked questions
What is loan-to-value (LTV)?+
The loan as a percentage of the property price. A 10% deposit means 90% LTV. Lower LTVs usually get better rates.
How much can I borrow?+
Lenders often lend around 4 to 4.5 times your household income, after checking your spending.
Should I overpay or save?+
If your mortgage rate is higher than what your savings earn after tax, overpaying usually saves more.