Financial planning: Mortgage calculator

Mortgage planning tool

Mortgage calculator

Estimate your monthly mortgage payments and total mortgage cost before you apply.

⭐ 5.0/5 • 226 Google & Facebook reviews

Regulated by the Financial Conduct Authority · No. 792412

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 does the calculator work?

Set the property value, deposit, interest rate and mortgage term. The calculator estimates monthly repayments using an amortising repayment model. Results are indicative.

Mortgage details

£300,000
£30,000

Minimum deposit depends on the lender and product.

4.5%
25 years

The calculator does not include product fees, valuation costs, insurance or future interest rate changes.

Results

Monthly payment
£1,500.75
estimated / month
Mortgage amount£270,000
LTV (Loan to Value)90.0%
Total mortgage cost£450,224
Total interest£180,224
Porozmawiaj z doradcą

Need a more accurate estimate?

Calculators show indicative figures. An adviser can check realistic options after reviewing your situation.

Free consultation

How the mortgage calculator works

The estimate uses a standard repayment-mortgage calculation, where each monthly payment contains interest and capital. Try more than one rate and term rather than treating a single result as a forecast.

  • 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, the property and stress-tested future payments.

  • 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.

Example mortgage calculation

For a £300,000 property with a £30,000 deposit, the loan is £270,000. At 4.5% over 25 years the calculator gives an indicative repayment, but the actual product and affordability assessment may differ.

Property price
£300,000
Deposit
£30,000 (10%)
Mortgage
£270,000
Assumption
4.5% over 25 years

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 lender-specific stress tests can increase or reduce the amount available.

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.

The results are estimates only and are not a mortgage offer, mortgage advice or a guarantee of lending. Actual borrowing, costs and monthly payments depend on lender criteria, product fees, credit profile, property type and full underwriting.

Client Reviews

What our clients say

5.0
226 reviews
Google
Verified reviews
S
Sylwia Zgórska
17/03/2026
Google · Translated from Polish
Mortgage + Insurance

"I highly recommend Mariusz Wasiluk (mortgage broker) and Magdalena Kurowska (insurance). We had great communication with them from start to finish. They explained everything clearly, were very helpful, and thanks to them the whole process was much less stressful. Great cooperation!"

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Working hours
Mon–Fri 9:00–18:00 Evenings and weekends by arrangement
We cover
Whole UK — 100% remote

Extend Finance is a mortgage broker regulated by the Financial Conduct Authority. Our registration number is 792412 — you can verify this at register.fca.org.uk

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