UK Mortgage Calculator
Enter the property price, your deposit, the interest rate and the term to see your monthly repayment and how the balance falls year by year. Includes a stamp duty estimate for England and Northern Ireland.
Property Details
Deposit: £60,000 · Loan: £240,000
Example rate, not a quote
Monthly Payment
£1,334
Loan Amount: £240,000
Principal
£240,000
Total Interest
£160,199
Total Payment
£400,199
Principal + Interest
£1,334/mo
Tax + Insurance
£0/mo
Stamp duty (England & Northern Ireland)
Stamp Duty Land Tax: £5,000 (1.67% of the price). Cash needed up front, deposit plus stamp duty: £65,000.
Buying in Scotland or Wales? Those nations charge different taxes (LBTT and LTT): see Revenue Scotland or the Welsh Government.
Rates: GOV.UK, checked 23 October 2026. Conveyancing and other costs are not included.
Year-by-Year Amortization
| Year | Principal | Interest | Balance |
|---|---|---|---|
| 1 | £5,317 | £10,691 | £234,683 |
| 2 | £5,561 | £10,447 | £229,122 |
| 3 | £5,816 | £10,192 | £223,306 |
| 4 | £6,084 | £9,924 | £217,222 |
| 5 | £6,363 | £9,645 | £210,859 |
| 6 | £6,655 | £9,352 | £204,203 |
| 7 | £6,961 | £9,047 | £197,242 |
| 8 | £7,281 | £8,727 | £189,961 |
| 9 | £7,616 | £8,392 | £182,346 |
| 10 | £7,965 | £8,043 | £174,380 |
| 11 | £8,331 | £7,677 | £166,049 |
| 12 | £8,714 | £7,294 | £157,335 |
| 13 | £9,114 | £6,894 | £148,221 |
| 14 | £9,533 | £6,475 | £138,688 |
| 15 | £9,971 | £6,037 | £128,717 |
| 16 | £10,429 | £5,579 | £118,287 |
| 17 | £10,908 | £5,100 | £107,379 |
| 18 | £11,409 | £4,599 | £95,970 |
| 19 | £11,933 | £4,075 | £84,037 |
| 20 | £12,482 | £3,526 | £71,555 |
| 21 | £13,055 | £2,953 | £58,500 |
| 22 | £13,655 | £2,353 | £44,845 |
| 23 | £14,282 | £1,726 | £30,563 |
| 24 | £14,938 | £1,070 | £15,625 |
| 25 | £15,625 | £383 | £0 |
How It Works
Enter the property price and your deposit; the loan is the price minus the deposit. A £300,000 home with a 20% deposit (£60,000) is a £240,000 loan. At 4.5% over 25 years the repayment is £1,334 a month and you would pay about £160,199 in interest over the term. In the early years most of each payment is interest, and the balance falls faster later, as the table under the calculator shows. The stamp duty panel estimates Stamp Duty Land Tax for England and Northern Ireland from the price you enter. On £300,000 that is £5,000 for a home mover, nothing for a first-time buyer and £20,000 for an additional property. The calculator covers repayment mortgages. It does not model interest-only loans, arrangement fees, or the change of rate when a fixed deal ends. The starting rate, deposit and price are only examples.
Formula
Monthly payment = L × r × (1 + r)^n / ((1 + r)^n − 1), where L is the amount borrowed (price minus deposit), r is the monthly rate (annual rate ÷ 12) and n is the number of monthly payments.
Stamp duty rates used (England and Northern Ireland)
These are the residential Stamp Duty Land Tax rates the calculator applies. It checks the price against each band and charges the rate on the part of the price inside that band. They were checked against GOV.UK on 23 October 2026.
| Part of the price | Standard rate |
|---|---|
| Up to £125,000 | 0% |
| £125,000 to £250,000 | 2% |
| £250,000 to £925,000 | 5% |
| £925,000 to £1,500,000 | 10% |
| Over £1,500,000 | 12% |
Sources: GOV.UK: residential property rates
First-time buyers and additional properties
First-time buyers pay no stamp duty up to £300,000 and 5% on the part from £300,000 to £500,000. The relief does not apply to a property priced above £500,000, so the standard rates are used instead. If buying the property leaves you owning more than one home, an extra 5% is added on top of the standard rates (there is an exception when you replace your main home and sell the old one within 36 months). Buyers who were not present in the UK for at least 183 days in the previous 12 months pay a further 2%. Some buyers and transactions are exempt, so use HMRC's own calculator before you commit.
Sources: GOV.UK: Stamp Duty Land Tax
Frequently Asked Questions
How is a UK mortgage repayment calculated?
The lender takes the amount borrowed, the monthly interest rate (annual rate ÷ 12 here) and the number of months, and works out the level payment that clears the loan exactly. Each payment covers that month's interest and the rest reduces the balance. This calculator is for repayment mortgages. With an interest-only mortgage you pay only the interest and still owe the full loan at the end, which this tool does not model.
How much stamp duty will I pay?
In England and Northern Ireland, on a £300,000 home a home mover pays £5,000, a first-time buyer pays £0, and someone buying an additional property pays £20,000. At £500,000 the figures are £15,000, £10,000 and £40,000. The calculator works it out for the price you enter. Scotland (LBTT) and Wales (LTT) have their own taxes and rates. The rates here were checked against GOV.UK on 23 October 2026; they can change at a Budget.
How much does the interest rate change my repayment?
On a £240,000 loan over 25 years the payment is £1,267 at 4%, £1,334 at 4.5%, £1,403 at 5%, £1,474 at 5.5%. Each half a percentage point adds roughly £69 to £71 a month.
Is a longer mortgage term a good idea?
It lowers the payment and raises the total interest. On £240,000 at 4.5%: 25 years is £1,334 a month and about £160,199 in interest; 30 years is £1,216 a month and about £197,776 in interest; 35 years is £1,136 a month and about £237,043 in interest. A longer term can also be a flexible choice if you can overpay when you have spare cash, within your lender's overpayment limits.
How does the deposit affect my payment?
A bigger deposit means a smaller loan. On a £300,000 home at 4.5% over 25 years, a 10% deposit gives a £270,000 loan and £1,501 a month; 20% gives £240,000 and £1,334; 25% gives £225,000 and £1,251. Lenders set their own minimum deposit, and a lower loan-to-value ratio usually unlocks better rates.
What happens when my fixed rate ends?
Many UK mortgages start with a fixed or discounted rate for a few years and then move to the lender's standard variable rate unless you switch deals. To see the effect, run the calculator again with the new rate and the number of years you have left.
Does it include council tax, insurance or fees?
Not unless you add them. The Advanced box lets you enter yearly property tax and home insurance if you want one monthly figure; council tax is normally paid separately from the mortgage. Solicitor, survey, valuation and mortgage arrangement fees are not included, and neither are stamp duty rates for Scotland or Wales.
Are the rate and prices real quotes?
No. The starting values are examples so the page opens with a realistic result. Use the rate on your own mortgage illustration or agreement in principle, and the actual purchase price.