ESTIMATED MONTHLY REPAYMENT
£0.00
Enter your mortgage details to calculate.
This calculator gives an estimate only. Actual mortgage repayments may vary depending on lender fees, product type, rate changes and individual circumstances.
How mortgage repayments are calculated
A repayment mortgage is normally paid back through regular monthly payments. Each payment covers the interest charged by the lender and repays part of the amount borrowed.
This calculator uses three main figures: the mortgage amount, the annual interest rate and the mortgage term. It estimates the monthly payment required to repay the mortgage over the selected term, assuming the interest rate remains unchanged.
In practice, mortgage rates can change. A fixed-rate mortgage normally keeps the same rate for an agreed period, while tracker and variable-rate mortgages may change over time. If the mortgage rate changes, the monthly repayment may also change. If you are considering replacing an existing mortgage with another product, the Remortgage Calculator can help you compare the potential costs.
Select Show your calculation to see the repayment formula and how your own figures are used to produce the estimated monthly payment.
Worked example: £200,000 mortgage over 25 years
Suppose you borrow £200,000 using a repayment mortgage over 25 years at an illustrative annual interest rate of 5%.
| Mortgage amount | £200,000 |
| Mortgage term | 25 years |
| Interest rate | 5% |
| Approximate monthly repayment | £1,169 |
| Number of monthly payments | 300 |
| Approximate total repaid | £350,754 |
| Approximate interest paid | £150,754 |
These figures are illustrative and assume the interest rate remains at 5% for the full 25-year term. Actual mortgage products may have changing rates, fees and other costs.
Understanding your mortgage calculation
Mortgage amount
The mortgage amount is the amount you borrow after taking your deposit into account. Borrowing more will usually increase both the monthly repayment and the total amount repaid.
Interest rate
The interest rate is the percentage charged by the lender for borrowing the money. Because mortgages can run for many years, even a relatively small difference in the interest rate can have a significant effect on monthly repayments and the total interest paid. To explore the effect of interest more broadly, the Interest Awareness Calculator can help show how interest changes the overall cost of borrowing over time.
Mortgage term
The mortgage term is the length of time over which the mortgage is scheduled to be repaid. A longer term will usually reduce the monthly repayment because the balance is spread across more payments, but it can increase the total interest paid.
A shorter term will normally increase the monthly repayment but may reduce the total interest paid over the life of the mortgage.
Comparing mortgage terms
After entering your mortgage details, you can compare your original mortgage term with up to two alternative terms without changing the original calculation.
For example, a 25-year mortgage can be compared with 20-year and 30-year terms using the same mortgage amount and interest rate. This makes it easier to see the trade-off between the monthly repayment and the length of time over which interest is charged.
The mortgage balance graph shows how the outstanding balance changes through time for each active term. Hover or tap across a line to see the mortgage position at different points during the term.
You can also change the interest rate in the main calculator to explore how a different rate affects the repayment, total amount repaid and total interest.
Repayment mortgages and interest-only mortgages
This calculator is designed primarily for a standard repayment mortgage.
With a repayment mortgage, each monthly payment covers the interest charged and repays part of the mortgage balance. If all scheduled payments are made and the terms do not change, the mortgage should normally be repaid by the end of the term.
An interest-only mortgage works differently. Monthly payments generally cover the interest charged without reducing the original amount borrowed. The capital must normally be repaid separately at the end of the mortgage term, so a separate repayment plan is required.
What can change your actual mortgage payment?
The figure produced by this calculator is an estimate. Actual mortgage payments can differ because of:
- changes in the mortgage interest rate
- fixed, tracker or variable-rate mortgage products
- arrangement or product fees
- fees added to the mortgage balance
- overpayments or lump-sum repayments
- payment holidays or changes to the mortgage term
- interest-only or other repayment structures
- individual lender calculations and rounding
If you are considering paying more than your scheduled monthly repayment, the Mortgage Overpayment Calculator can help you explore how regular overpayments could reduce total interest and shorten the mortgage term.
If your existing mortgage deal is changing or approaching its end, you can also use the Remortgage Calculator to explore how a replacement mortgage may compare.
What this calculator includes and excludes
The calculator estimates the monthly repayment for a repayment mortgage using the mortgage amount, annual interest rate and mortgage term entered.
It does not automatically include:
- mortgage arrangement fees
- valuation fees
- legal or conveyancing costs
- insurance costs
- early repayment charges
- changes in interest rates during the mortgage
- property purchase taxes such as Stamp Duty Land Tax, Land and Buildings Transaction Tax or Land Transaction Tax
These additional costs may materially affect the overall cost of buying or financing a property. The Mortgage Cost Awareness Calculator can help you consider mortgage costs beyond the monthly repayment itself.
Property purchase taxes vary across the UK. For purchases in England or Northern Ireland, use the Stamp Duty Calculator. For purchases in Scotland, use the LBTT Calculator. For purchases in Wales, use the LTT Calculator.
UK mortgage information
Mortgage products in the UK can include fixed-rate, tracker, variable-rate, repayment and interest-only arrangements. The exact terms, fees and eligibility requirements depend on the lender and mortgage product.
Mortgage affordability is assessed separately by lenders and may take account of income, regular expenditure, existing debts, credit history and other circumstances. A monthly repayment estimate does not mean that a lender will approve a mortgage for that amount.
If you want to estimate how much you may be able to borrow based on income and other factors, use the Affordability Calculator.
Important note
This calculator is for general informational purposes only. It does not provide mortgage, financial or legal advice and should not be used as a substitute for a formal mortgage illustration or personalised advice from a suitably qualified professional.
Frequently Asked Questions
How are mortgage repayments calculated?
For a standard repayment mortgage, the monthly payment is calculated using the mortgage amount, interest rate and mortgage term. Each payment covers the interest charged and repays part of the amount borrowed.
Does this calculator include lender fees?
No. The calculator estimates the mortgage repayment itself and does not automatically include arrangement fees, valuation fees, legal costs or other charges.
Can mortgage interest rates change?
Yes. Fixed rates normally remain unchanged for the agreed fixed period, while tracker and variable rates can change. If the rate changes, the monthly repayment may also change.
Does a longer mortgage term reduce monthly repayments?
Usually, yes. Spreading the mortgage across more years generally reduces the monthly payment, but it may increase the total interest paid because the mortgage remains outstanding for longer.
What is the difference between repayment and interest-only mortgages?
A repayment mortgage gradually repays both interest and the amount borrowed. With an interest-only mortgage, monthly payments generally cover the interest, while the original amount borrowed normally has to be repaid separately at the end of the term.
Can this calculator be used for buy-to-let mortgages?
It can provide a general repayment estimate, but many buy-to-let mortgages use interest-only structures and lenders may apply different affordability and eligibility criteria. If you are assessing an investment property, the Rental Yield Calculator can help compare the property’s rental income with its purchase price.
Does this calculator show how much I can borrow?
No. This calculator estimates repayments for a mortgage amount you enter. Borrowing limits and affordability are assessed separately by lenders. Use the Affordability Calculator for a simple borrowing estimate.
Sources and review
This calculator and its supporting information were reviewed in September 2026.
Useful official and independent information about mortgages is available from:
- GOV.UK – Money and Pensions Service mortgage repayment calculator information
- Bank of England – how interest rates affect borrowing and mortgages
- Financial Conduct Authority – mortgage support and interest rate information
Quick Calculators UK aims to keep calculator information accurate and useful. Mortgage products, interest rates and regulatory requirements can change, so users should check current information before making financial decisions.