Estimate monthly mortgage payments before you commit.
Work out the monthly repayment, total interest, total repaid, deposit percentage, and loan-to-value for a repayment mortgage.
Practical purchase planning
Model a home price, deposit, rate, and term before comparing overpayments or affordability.
Estimated monthly payment
£1,334
Based on a 80% loan-to-value mortgage.
Inputs
Mortgage details
Estimate
Results
Monthly repayment
£1,334
Mortgage amount
£240,000
Loan-to-value
80%
Total interest
£160,199
Total repaid
£400,199
Assumes a repayment mortgage with a fixed interest rate for the full term. Fees, insurance, taxes, and rate changes are not included.
Assumptions
Assumptions to review
Check these inputs before relying on the result.
- Mortgage balance
- £240,000
- Property price minus deposit. This is the balance being repaid.
- Interest rate
- 4.5%
- Assumed to stay fixed for the full mortgage term.
- Mortgage term
- 25 years
- The number of years used to spread the repayment mortgage.
- Product fees
- Not included
- Product fees, insurance, taxes, and future rate changes are outside this estimate.
Last reviewed
12 June 2026
Interest method
Monthly interest is estimated from the annual rate unless a page states a different method. Lender figures can use daily interest, product-specific rules, and exact payment dates.
Educational scope
UK-focused calculator estimate. It explains trade-offs and does not make a personal recommendation.
How this is calculated
- The annual interest rate is converted into a monthly rate.
- Each month, interest is estimated on the current mortgage balance.
- The repayment first covers that month's interest. The rest reduces the balance.
- As the balance falls, less interest is charged and more of each payment goes towards the debt.
Main limitations
- The estimate uses the values entered on this page and does not check lender eligibility, affordability, credit history, product availability, or personal tax treatment.
- Fees, ERCs, insurance, valuation costs, legal costs, rate changes, and overpayment rules are included only where the calculator explicitly asks for them.
Results are estimates based on the assumptions shown here. They are not financial advice and can differ from lender figures because real products, fees, rate changes, overpayment rules, and repayment timing vary.
Learn the maths
Work out a mortgage repayment by hand
Follow a plain-English lesson covering the inputs, repayment formula, variable definitions, a UK worked example, common mistakes, and practice questions with fully worked solutions.
Open the repayment lessonBalance path
Estimated mortgage balance over time
| Year | Balance | Interest paid | Principal paid |
|---|---|---|---|
| 0 | £240,000 | £0 | £0 |
| 5 | £210,859 | £9,645 | £6,363 |
| 10 | £174,380 | £8,043 | £7,965 |
| 15 | £128,717 | £6,037 | £9,971 |
| 20 | £71,555 | £3,526 | £12,482 |
| 25 | £0 | £383 | £15,625 |
Important disclaimer
This calculator provides estimates only and does not constitute financial advice. Mortgage costs may vary depending on lender fees, product fees, insurance, taxes, rate changes, repayment rules, and your final mortgage offer.