UK Mortgage Calculator
See what a mortgage actually costs you, month by month.
Enter the property price, deposit, interest rate and term below. Every figure updates as you type — no submit button, no waiting.
Monthly repayment
£0
- Total repaid
- £0
- Total interest
- £0
- Loan-to-value
- 0%
Balance over time
How your outstanding balance and cumulative interest move across the life of the loan.
How this figure is worked out
The calculator uses a standard repayment mortgage formula, which spreads both the capital you borrowed and the interest across equal monthly payments. Early payments are weighted more toward interest; later payments pay off more of the capital, even though the total payment stays the same throughout the term.
What changes your monthly payment most
Rate and term move the figure more than most people expect. Stretching a loan from 25 to 35 years lowers the monthly payment but usually increases the total interest paid by a large margin, because you're paying interest for an extra decade. A larger deposit reduces the loan amount directly, which lowers both the payment and the total interest.
What this calculator doesn't include
This tool estimates capital and interest only. It doesn't account for arrangement fees, early repayment charges, changes in interest rate after a fixed period ends, buildings insurance, or ground rent and service charges on leasehold properties. Treat the result as a starting estimate, not a mortgage offer.
Frequently asked questions
How is a mortgage repayment calculated?
Your monthly repayment is worked out using a standard amortising loan formula, which spreads the amount you've borrowed plus interest evenly across every monthly payment for the full term. Even though each payment is the same size, the mix changes over time: early payments are weighted more toward interest, and later payments pay off more of the actual capital.
Does this mortgage calculator include fees and insurance?
No. This calculator estimates capital and interest repayments only. It doesn't include arrangement or product fees, early repayment charges, buildings insurance, ground rent, service charges, or what happens to your rate after a fixed or discounted period ends. Treat the result as a starting estimate rather than a full cost of ownership.
How does a larger deposit affect my mortgage?
A larger deposit directly reduces the amount you need to borrow, which lowers your monthly repayment, reduces the total interest charged over the life of the loan, and improves your loan-to-value (LTV) ratio. A lower LTV can also help you qualify for lower interest rates from some lenders.
Does a longer mortgage term lower monthly repayments?
Yes — spreading the same loan over more years reduces the size of each monthly payment. However, it usually increases the total interest you pay overall, since you're paying interest for a longer period. A shorter term means higher monthly payments but typically less interest paid in total.