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Mortgage calculator

Estimate monthly repayments based on the property price, deposit, interest rate and term.

Property price

Deposit

Interest rate

Mortgage term

This calculator gives an estimate only and does not include fees, insurance, taxes or lender-specific affordability checks.

Estimated monthly repayment

£0

Mortgage amount£0
Deposit percentage0%
Total repayments£0
Total interest£0

What your result means

Your estimate shows what a repayment mortgage could cost each month, and over its full term.

Enter the property price, your deposit, an annual interest rate and the number of years you want to repay over. To compare scenarios, change one input at a time. Unsure about a word? The glossary explains the mortgage terms used on this page.

Estimated monthly repayment: The regular monthly payment towards the money borrowed and the interest charged.
Mortgage amount: The property price minus your deposit. This is your starting loan, also called capital.
Deposit percentage: Your deposit as a share of the property price. A £25,000 deposit on a £250,000 property is 10%.
Total repayments: All the calculated monthly payments added together. This includes the original loan and interest, but not your deposit or fees.
Total interest: The estimated cost of borrowing over the whole term, excluding fees. It is total repayments minus the original mortgage amount.

A repayment estimate is not an approval. This tool does not assess affordability or eligibility, or tell you how much a lender will offer.

Methodology: how we calculate repayments

We use a standard capital-and-interest repayment calculation, known as amortisation. It works out equal monthly payments that would reduce the mortgage balance to zero by the end of the term.

Work out the amount borrowed. Property price minus deposit gives the mortgage amount.
Convert the inputs. We divide the annual interest rate by 12 to get a monthly rate, and multiply the term in years by 12 to get the number of payments.
Calculate the monthly payment. Each payment covers that month's interest and pays back some capital. At a 0% rate, we divide the loan equally across the number of months.
Add up the totals. Total repayments equal the unrounded monthly payment multiplied by the number of months. Total interest is that figure minus the starting loan.

See the calculation formula

M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)

M is the monthly payment. P is the starting loan. r is the monthly interest rate as a decimal: the annual percentage divided by 100, then by 12. n is the number of monthly payments. The raised n means multiply (1 + r) by itself n times. At 0% interest, the formula is simply M = P ÷ n.

The assumptions behind your estimate

The interest rate stays the same for the entire mortgage term. We do not model an initial fixed-rate deal followed by a different rate.
Interest is calculated monthly on the remaining loan balance, with payments at the end of each month. A lender's daily interest method or first-payment date may give a different result.
All payments are made on time, with no overpayments, missed payments or fees added to the loan.
This is a repayment calculation, not an interest-only mortgage calculation.

Rates and rounding. The pre-filled 4.75% is an editable illustration, not a live mortgage offer. Enter an annual interest rate excluding fees, not an APRC. Money is displayed to the nearest pound; totals use the full, unrounded calculation. Multiplying the displayed monthly payment by the number of months can therefore give a slightly different total.

Two simple worked examples

Both examples use a £250,000 property, a 4.75% annual interest rate and a 25-year term. Only the deposit changes. These are illustrations, not available mortgage deals.

Example 1 · 10% deposit

A £25,000 deposit

£250,000 − £25,000 = £225,000 borrowed

£1,283

estimated monthly repayment

Number of payments: 300
Total repayments: £384,829
Total interest: £159,829

Example 2 · 20% deposit

A £50,000 deposit

£250,000 − £50,000 = £200,000 borrowed

£1,140

estimated monthly repayment

Number of payments: 300
Total repayments: £342,070
Total interest: £142,070

What changes? Putting in another £25,000 means borrowing £25,000 less. With the same rate and term, monthly repayments are about £143 lower and total interest is about £17,759 lower. The extra deposit is your money paid towards the purchase, not a discount on the property.

A closer look: deposit, term and interest rate

Imagine buying a £300,000 home. Start with option A, then compare a larger deposit, a shorter term and a higher interest rate. Each row is a separate full-term estimate.

On a small screen, swipe the table sideways to see every figure.

Illustrative repayments on a £300,000 property
Scenario	Deposit	Borrowed	Rate	Term	Monthly	Total interest	Total repayments
A · Starting point	£30,000	£270,000	4.75%	30 years	£1,408	£237,041	£507,041
B · Larger deposit	£60,000	£240,000	4.75%	30 years	£1,252	£210,703	£450,703
C · B, shorter term	£60,000	£240,000	4.75%	25 years	£1,368	£170,485	£410,485
D · C, higher rate	£60,000	£240,000	5.75%	25 years	£1,510	£212,957	£452,957

A to B: a larger deposit. Borrowing falls by £30,000. Loan-to-value (LTV) falls from 90% to 80%. We keep the rate unchanged to show the effect of borrowing less; a lender's actual pricing may differ.
B to C: five fewer years. Monthly repayments rise by about £116, but total interest falls by about £40,219. A lower overall interest bill comes with a higher monthly commitment.
C to D: a higher rate. Raising the annual rate from 4.75% to 5.75% increases the monthly estimate by about £142 for the same loan and term.

Differences use unrounded calculations, then round to the nearest pound. Totals exclude deposits and fees. Option D does not predict a future rate or model a rate change part-way through the mortgage.

Costs not included in your estimate

Your monthly mortgage payment is only one part of the cost of buying and owning a home. Allow separately for:

Arrangement or product fees, and any broker fee.
Valuation fees, a property survey and legal fees.
Property purchase taxes, where payable, and moving costs.
Insurance, household bills and maintenance.
Any early repayment charge if you repay early or switch an existing mortgage.

Fees added to a mortgage can also attract interest. This calculator does not automatically include them. Read MoneyHelper's guide to mortgage and moving costs for a fuller breakdown.

Your home may be repossessed if you do not keep up repayments on your mortgage. Repossession means the lender can take and sell the property through a legal process to recover money owed.

Mortgage glossary: the words explained

Plain-English definitions of the mortgage and finance terms used on this page. Dotted links in the explanations take you straight to the relevant definition.

Affordability / affordability check: Whether repayments fit your finances. A lender assesses income, spending and other commitments to decide whether you can manage the payments.
Amortisation: Gradually paying off a loan through regular payments covering both interest and part of the amount borrowed. With an unchanged rate and payment, the interest share falls as the loan balance reduces.
APRC (annual percentage rate of charge): A percentage showing the overall annual cost of a mortgage, including interest and applicable fees, using assumptions over its full term. It is not the interest-rate input this calculator uses.
Arrangement fee / product fee: A fee a lender may charge to set up a particular mortgage deal. It is separate from interest.
Balance / outstanding balance: The amount of the loan still unpaid at a particular point in time.
Broker / credit broker: A business that helps arrange credit or introduces you to finance providers. A broker does not itself lend you the money. A broker fee is a charge for its service.
Capital / principal: The money borrowed, separate from interest and fees. Repaying capital reduces the loan balance.
Credit / finance: Money made available to borrow and repay later, usually with interest or charges.
Credit history: A record of how you have used and repaid borrowing. A lender may consider this when deciding on an application.
Deposit / deposit percentage: Your contribution towards the property price, separate from the mortgage. The percentage is your deposit divided by the property price, multiplied by 100.
Early repayment charge: A charge that may apply if you repay some or all of a mortgage early, or change deals during a specified period. The mortgage agreement sets the conditions.
Eligibility: Whether you meet a lender's requirements for a particular mortgage. An estimated repayment does not establish eligibility.
Estimate / illustration / quote: An estimate or illustration shows a possible cost using stated inputs and assumptions. A quote sets out proposed terms from a provider; it is not necessarily a final lending approval.
Financial Conduct Authority (FCA): A UK regulator of financial services. Being authorised and regulated means a firm has permission for specified activities and must follow the rules that apply to them.
Fixed-rate deal / deal period: A mortgage arrangement where the interest rate stays unchanged for an agreed period. That period may be shorter than the full mortgage term.
Insurance: Cover bought to help pay for specified losses or events, subject to the policy's conditions. The calculator does not include its cost.
Interest / interest rate: Interest is the charge for borrowing money. An interest rate expresses that charge as a percentage. This calculator takes an annual rate excluding fees and divides it by 12 for its monthly calculation.
Interest-only mortgage: A mortgage whose regular payments cover interest without reducing the original loan. A separate way of repaying that loan is needed. This calculator does not model it.
Legal fees: Charges for the legal work involved in buying a property or arranging a mortgage.
Lender: The organisation providing the loan and setting its lending requirements.
Loan-to-value (LTV): The mortgage amount as a percentage of the property's value. In these purchase examples, loan ÷ property price × 100. A £240,000 loan on a £300,000 property is 80% LTV.
Methodology: The method, calculation steps and assumptions used to produce an estimate.
Monthly repayment: The regular amount paid each month. For a repayment mortgage, it covers interest and some of the money borrowed.
Mortgage adviser: A professional who assesses your circumstances and recommends a suitable mortgage from the range they can advise on. Ask which lenders they cover and what their service costs.
Mortgage / mortgage amount / loan amount: A mortgage is a loan secured against a property: the property can be used to recover money if repayments are not kept up. Here, the mortgage amount is the property price minus the deposit.
Mortgage term / repayment period: The total length of time planned for repaying the mortgage. It is different from the length of a fixed-rate deal.
Overpayment: A payment above the amount normally due. It can reduce the loan balance sooner; limits or charges may apply.
Property price / property value: The price is the amount paid for a property. Its value is an assessment of what it is worth, which may differ. This calculator uses the price you enter.
Property purchase taxes: Taxes that may be payable when buying a property. The rules depend on where the property is and the buyer's circumstances.
Remortgage: Replacing an existing mortgage on a property with a new one, commonly with a different lender.
Repayment mortgage / capital-and-interest mortgage: A mortgage where regular payments cover interest and reduce the loan, aiming to repay it fully by the end of the term.
Repossession: The legal process through which a lender takes possession of a property after repayments are not kept up. The property can be sold to recover the debt.
Rounding / unrounded calculation: Rounding shortens a number for display, here to the nearest pound. An unrounded calculation keeps the more precise number when working out totals.
Property survey: An inspection of a property's condition to identify issues. It is different from a lender's valuation.
Total interest: All interest in the calculator's full-term estimate. It excludes the money originally borrowed and any fees.
Total repayments / total amount repayable: On this calculator, the sum of all estimated monthly mortgage payments: the original loan plus interest. It excludes your deposit and fees.
Valuation / valuation fee: A lender's assessment of a property's value, and any charge for it. A valuation is not the same as a detailed condition survey.

Frequently asked questions

Which interest rate should I enter?

Use the annual mortgage interest rate you want to explore, excluding fees. Do not use the APRC. The default 4.75% is illustrative, and the tool assumes the entered rate continues for the whole term.

Why might a lender's figure be different?

A lender may calculate interest daily, use different payment dates, add agreed fees to the loan or show payments after an initial deal ends. Compare its quote and assumptions with this calculator's methodology.

Can this tell me how much I can borrow?

No. It calculates repayments for the amount entered. A lender separately considers your income, spending, credit history and other requirements before deciding what it may offer.

Does a lower monthly payment mean a cheaper mortgage?

Not necessarily. In this model, extending the term lowers the monthly payment but increases total interest when the loan and positive interest rate stay the same. Compare both the monthly commitment and total interest.

Can I use this for an interest-only mortgage or overpayments?

No. It assumes regular capital-and-interest payments with no extra payments. The mortgage overpayment calculator explores extra payments separately; check its assumptions and your lender's conditions.

Explore your next step

Use the estimates to prepare questions and compare scenarios. For a borrowing decision, check the lender's actual terms and consider speaking with a mortgage adviser.

About this explanation. The methodology describes this calculator's existing calculation. Examples are illustrations using the stated assumptions, not recommendations or mortgage offers.

Further reading: MoneyHelper on repayment and interest-only mortgages, interest rates and APRC, and mortgage and moving costs. The FCA explains how to check a firm's authorisation.