Mortgage Calculator
Use this mortgage calculator to find your monthly payment, loan-to-value and total interest from the price, deposit, rate and term.
Quick answer: The monthly payment on a repayment mortgage depends on the loan, the interest rate and the term. A £250,000 mortgage at 4.5% over 25 years costs £1,389.58 a month. Enter the property price, deposit, rate and term in the calculator to see your own payment, total interest and a year-by-year balance table.
How to use the Mortgage Calculator
- Enter price and deposit. Type the property price and the deposit you can put down; the loan amount and loan-to-value are worked out for you.
- Enter the rate and term. Add the annual interest rate and the length of the mortgage in years.
- Press Calculate. Read the monthly payment, total interest and the yearly balance table, and add running costs if you want the full monthly figure.
Formula & worked example
Formula: Payment = L × r ÷ (1 − (1 + r)^−n), with r = annual rate ÷ 12 and n = years × 12. Loan-to-value = loan ÷ price.
Example: £350,000 price, 15% deposit, 4.5% over 30 years: loan £297,500, payment about £1,507.39, total interest about £245,160. (Figures in GBP for UK mode; switch to US mode for dollars and a down payment.)
Method & source: Standard fixed-rate repayment (amortisation) formula. See how we test our calculators.
Next step: try loan repayments with extra payments or UK take-home pay.
Mortgage Payments, Explained
A mortgage calculator estimates the regular payment on a home loan from the property price, your deposit, the interest rate and the length of the mortgage. It also shows how much interest you will pay in total and how quickly the balance falls.
This mortgage calculator for your monthly payment uses a standard repayment (capital and interest) mortgage, offers UK and US wording, and lets you add running costs such as insurance so you can see the full monthly picture.
From Loan Amount to Monthly Payment
Enter the price, your deposit or down payment as an amount or a percentage, the rate and the term.
- Loan amount: property price minus deposit, with the loan-to-value percentage shown.
- Monthly payment: the fixed instalment that repays the loan exactly over the term.
- Total interest: the extra you pay on top of the amount borrowed over the whole term.
- Rate check: a small table shows the payment if the rate is 1% lower, 1% higher or 2% higher.
- Yearly table and chart: interest paid, capital repaid and remaining balance for every year.
The payment shown is for capital and interest. Fees, taxes and rate changes after an initial fixed period are not included, so treat the result as a planning estimate.
Why Calculating Your Mortgage Matters
A mortgage is usually the largest debt you will take on. A few minutes of maths before you commit can save thousands.
- Find out what monthly payment fits your budget before house-hunting.
- See how a bigger deposit lowers both the payment and the total interest.
- Compare a shorter term with a longer one and the interest each costs.
- Stress-test your budget against higher interest rates.
- Understand how slowly the balance falls in the early years.
Use a mortgage calculator early, then confirm figures with a lender or independent adviser before you make an offer.
Worked walkthrough: a £350,000 home
Suppose a property costs £350,000 and you put down 15% (£52,500). The loan is £297,500, an 85% loan-to-value. At 4.5% over 30 years the monthly payment is about £1,507.39, and total interest over the term is roughly £245,160, so you repay about £542,660 in all. The rate table shows how sensitive this is: at 5.5% the payment rises to about £1,689.17, and at 3.5% it falls to about £1,335.91. The yearly table shows that in year one most of each payment is interest, with the capital share growing each year.
Things to check before you rely on a payment figure
- Do not stretch your budget to the maximum payment: leave room for maintenance, insurance and a rise in the interest rate.
- Compare a longer term with a shorter one. The longer term lowers the payment but usually costs far more interest overall.
- A larger deposit often reduces the interest rate you are offered as well as the amount borrowed – try 5%, 10% and 20% to see the effect.
- Check whether your lender allows overpayments and whether there is an early-repayment charge before assuming you can pay the loan off early.
- Remember the rate may change after an initial fixed or introductory period. Use the rate table to test a higher rate.
Repayment and interest-only mortgages
This calculator assumes a repayment mortgage, where each payment covers the interest and repays part of the loan, so the debt is cleared by the end of the term. On an interest-only mortgage you pay only the interest, and the full amount is still owed at the end. On a £200,000 loan at 5%, interest-only costs £833.33 a month, while a 25-year repayment mortgage costs £1,169.18 a month but leaves nothing owing. (Figures in GBP for UK mode; switch to US mode for dollars.)
The trade-off between term and cost
A longer term makes the monthly payment smaller but adds a lot of interest.
| Term | Monthly payment | Total interest |
|---|---|---|
| 20 years | £1,319.91 | £116,779 |
| 25 years | £1,169.18 | £150,754 |
| 30 years | £1,073.64 | £186,512 |
How sensitive the payment is to the rate
On £200,000 over 25 years the monthly payment is £1,055.67 at 4%, £1,169.18 at 5% and £1,288.60 at 6%, roughly £114 more for the step from 4% to 5% and £119 more from 5% to 6%. The rate table in the calculator shows the payment at a rate 1% lower, 1% higher and 2% higher, which is useful for stress-testing your budget before an introductory rate ends.
Deposit and loan-to-value
The deposit reduces the amount you borrow, and loan-to-value (LTV) expresses the loan as a share of the property price. A larger deposit lowers the payment and often qualifies for a better rate, which the calculator cannot know, so try a few scenarios. On a £300,000 property at 5% over 25 years:
| Deposit | Loan (LTV) | Monthly payment |
|---|---|---|
| 5% | £285,000 (95%) | £1,666.08 |
| 10% | £270,000 (90%) | £1,578.39 |
| 20% | £240,000 (80%) | £1,403.02 |
| 25% | £225,000 (75%) | £1,315.33 |
Where the first year’s payments go
Early payments are mostly interest. On the £200,000, 5%, 25-year example, the first 12 payments total about £14,030, of which about £9,906 is interest and only about £4,124 repays the loan, leaving £195,876 owed. The yearly table and chart show this shift, which is why overpaying early has the biggest effect.
What the payment does not include
The figure is a planning estimate for capital and interest. You can add insurance and other monthly costs, plus property tax in US mode, to see the payment with running costs. Fees, purchase taxes such as stamp duty, and rate changes after a fixed period are not included, and lender rules vary, so speak to a mortgage adviser before you commit – GOV.UK's guide to buying a home covers the wider process. To compare against other borrowing use the loan repayment calculator, to build a deposit use the savings goal calculator, and to see how money you set aside could grow, try the compound interest calculator.
Monthly payment on common mortgage sizes
Searching for a 120k mortgage calculator, a 150k mortgage or a 65,000 mortgage? The table shows the monthly repayment on six common mortgage amounts at an example rate of 4.5% a year, over 25 and 30 years, with the total interest over 25 years. It covers capital and interest only, so add buildings insurance and any other running costs.
| Mortgage amount | 25 years | 30 years | Interest over 25 years |
|---|---|---|---|
| £65,000 | £361.29 | £329.35 | £43,387 |
| £110,000 | £611.42 | £557.35 | £73,425 |
| £120,000 | £667.00 | £608.02 | £80,100 |
| £150,000 | £833.75 | £760.03 | £100,125 |
| £190,000 | £1,056.08 | £962.70 | £126,825 |
| £250,000 | £1,389.58 | £1,266.71 | £166,874 |
To work backwards from a monthly budget, divide the payment by the factor for your rate and term. At 4.5% over 25 years, a monthly payment of £1,000 supports a loan of about £179,910, £1,200 supports about £215,892, and £1,500 supports about £269,865, before any deposit is added to find the property price. Try your own rate, deposit and term in the calculator above.
Frequently Asked Questions (FAQs)
With the amortisation formula: payment = loan × r ÷ (1 − (1 + r)^−n), where r is the monthly interest rate and n is the number of monthly payments. The calculator does this for you.
Requirements vary by lender and country, and a larger deposit usually unlocks better rates. Try different percentages to see how the payment and loan-to-value change.
LTV is the loan as a percentage of the property price. Borrowing £240,000 against a £300,000 property is an 80% LTV. Lower LTVs often qualify for lower interest rates.
No. It assumes a repayment mortgage, where every payment covers interest and reduces the loan. Interest-only payments would be just the balance × the monthly rate.
Each month the lender charges interest on the balance still owed: the balance × the annual rate ÷ 12. The rest of the fixed payment repays the loan. On £200,000 at 5% over 25 years the payment is £1,169.18; in the first month £833.33 of it is interest and only £335.85 repays the loan. The next month the balance is a little lower, so slightly less interest is charged. That is why early payments are mostly interest.
At 4.5% over 25 years, a monthly repayment of £1,200 supports a loan of about £215,892, on capital and interest only. A higher rate or a shorter term supports a smaller loan. Enter your own rate, term and deposit in the calculator to find the monthly payment for a particular property price.
At 4.5% over 25 years, a £250,000 repayment mortgage costs about £1,390 a month. Change the rate, term or deposit to see your own figure.
Total interest is the sum of all payments minus the amount borrowed. Because interest is charged on the outstanding balance every month, over 25 years it can come close to the loan itself: £200,000 at 5% costs £150,754.02 in interest, or £350,754.02 in total. A shorter term or an overpayment reduces it. The calculator shows the total, together with a yearly table of interest, principal and balance.
Yes. Switch between UK (deposit) and US (down payment) wording and the same repayment maths applies.
Yes. Add insurance and other monthly costs (and property tax in US mode) and the calculator shows the payment plus running costs.
Estimates only – not financial advice. Results assume a fixed rate for the whole term and a repayment (capital and interest) mortgage, with no fees, taxes or rate changes. Lenders’ offers and affordability rules differ. Speak to a lender or independent mortgage adviser before you borrow. See our full disclaimer.