TL;DR
What this mortgage calculator tells you
The calculator estimates a repayment mortgage payment from the property price, deposit, interest rate and term. It also shows the loan amount, LTV, total repayments and estimated interest.
It does not assess lender affordability or produce a mortgage offer. Income, commitments, credit profile, property type, fees and underwriting can change the options available.
Calculator / tool
Mortgage calculator
How the mortgage calculator works
The estimate assumes monthly capital-and-interest repayments and the selected annual interest rate staying unchanged throughout the full mortgage term. The default 4.5% is illustrative, not a current mortgage offer. An initial fixed-rate deal can end before the mortgage term, so try more than one rate rather than treating a single result as a forecast.
The sliders allow property values from £50,000 to £2 million in £5,000 steps, deposits from £0 to the property value in £1,000 steps, rates from 1% to 10% in 0.1 percentage-point steps and terms from 5 to 35 years in one-year steps. These are tool limits, not lending eligibility rules or available product ranges.
- Property value and cash deposit set the loan amount.
- Interest rate changes the monthly payment and total interest.
- A longer term can reduce the payment but increase total interest.
- A larger deposit can reduce LTV and may improve product choice.
Monthly payment is not the same as affordability
A manageable-looking payment does not mean a lender will approve the loan. Lenders review verified income, household spending, credit commitments, dependants and the property. They also consider future interest-rate rises where applicable; the rules include exceptions, so there is no single stress test for every application.
Total repayments means the loan capital plus the interest estimated over the full term. It excludes your deposit and other purchase costs, so it is not the full cost of buying the property.
- Compare the result with essential household spending.
- Keep cash for tax, legal work, survey and moving costs.
- Allow for possible rate changes after a fixed period.
- Use an affordability review before making a binding commitment.
What the calculator does not include
The result excludes product fees, broker fees where applicable, valuation, survey, legal fees, insurance, taxes and changes in interest rates. It also assumes a capital-and-interest repayment mortgage and does not model an interest-only product.
A lender’s interest calculation method, payment dates and first-payment interest can produce different figures. Check the payment schedule in your mortgage documents.
Example mortgage calculation
For a £300,000 property with a £30,000 deposit, the loan is £270,000 at 90% LTV. Assuming 4.5% interest throughout 25 years gives the estimates below. Totals use the unrounded monthly payment and are rounded to the nearest pound; actual lender payments may differ.
- Property price
- £300,000
- Deposit
- £30,000 (10%)
- Mortgage
- £270,000
- LTV
- 90%
- Assumption
- 4.5% over 25 years
- Monthly payment
- £1,500.75
- Total repayments
- £450,224
- Total interest
- £180,224
Official sources
Frequently asked questions
Is this mortgage calculator a mortgage offer?
No. It is an illustrative calculation only. A lender must assess the applicants, supporting documents, credit profile and property before making an offer.
Why can lender affordability be different from this result?
This tool calculates a payment, while a lender assesses affordability. Income type, regular spending, credit commitments, dependants and future-rate checks where applicable can affect the amount available. Lender criteria and exceptions mean the assessment is not identical for every application.
Does the calculator include fees?
No. Product, valuation, legal, survey, insurance and broker fees where applicable are outside the result. Some mortgage fees can be added to a loan, but doing so normally means paying interest on them.
How does the mortgage term affect monthly payments?
A longer term normally lowers the monthly repayment because the balance is spread over more months. It can also increase the total interest paid and may be limited by age or lender criteria.
How does deposit size affect the mortgage?
A larger deposit reduces the loan and LTV. Lower LTV can open different products, but available rates and minimum deposits still depend on lender and property criteria.
Should I choose a shorter or longer mortgage term?
The right term balances an affordable payment with total interest and flexibility. Review the payment alongside your real budget and ask an adviser to compare suitable lender and product options.