Mortgage Calculator UK
Work out a UK mortgage and the tax on buying the home in one place. Type the price, your deposit, the interest rate and the term to get the monthly payment, the total repaid and the total interest. Then pick where the property is. The calculator shows Stamp Duty Land Tax for England and Northern Ireland, Land and Buildings Transaction Tax for Scotland or Land Transaction Tax for Wales, band by band, with first-time buyer relief and the rates for buyers who will own more than one home. The rates are for residential purchases, copied from GOV.UK, Revenue Scotland and the Welsh Revenue Authority on 15 October 2026.
Monthly payment
£1,334.00
Loan amount
£240,000.00 (80.00% loan to value)
Total repaid over 300 months
£400,198.96
Total interest
£160,198.96
The last of the 300 payments is £1,332.96. It clears the pence left over from rounding.
Stamp Duty Land Tax at main rates
£5,000.00
| Band | Rate | Taxed in band | Tax |
|---|---|---|---|
| Up to £125,000 | 0% | £125,000.00 | £0.00 |
| £125,001 to £250,000 | 2% | £125,000.00 | £2,500.00 |
| £250,001 to £925,000 | 5% | £50,000.00 | £2,500.00 |
| £925,001 to £1,500,000 | 10% | £0.00 | £0.00 |
| Above £1,500,000 | 12% | £0.00 | £0.00 |
| Total | £5,000.00 | ||
SDLT residential rates, first-time buyer relief and higher rates in force from 1 April 2025. Sources, opened on 15 October 2026: GOV.UK, Stamp Duty Land Tax: residential property rates and GOV.UK, Higher rates of Stamp Duty Land Tax.
The calculator does not cover the non-resident surcharge, company or trust purchases, shared ownership, leases or non-residential property. Money is worked out exactly and rounded to the penny.
How to use the Mortgage Calculator UK
- Type the property price in whole pounds. The mortgage and the tax both use it.
- Type your deposit as an amount in pounds or as a percentage of the price. The calculator shows the loan and the loan to value.
- Type the interest rate a year and the term in whole years, then pick repayment or interest-only.
- Pick the nation the property is in, then whether this will be your only home, your first home or one of several. Wales has no first-time buyer relief, so that choice shows only for England and Northern Ireland and for Scotland.
- Read the monthly payment, the total repaid, the total interest and the tax in each band. The results update as you type, so there is no button to press.
The mortgage and purchase tax formulas
Repayment: M = L × r × (1 + r)^n ÷ ((1 + r)^n − 1) At 0%: M = L ÷ n Interest-only: M = L × r Tax = sum over the bands of (part of the price in the band × the band rate)
L is the loan, which is the price minus the deposit. r is the yearly rate divided by 12, and n is the term in months. On an interest-only mortgage the loan is still owed at the end, so the total repaid is the interest plus the loan. The tax works in slices, and each band taxes only the part of the price inside it. Scotland's Additional Dwelling Supplement works differently. It is 8% of the whole price, added on top of LBTT. The calculator rounds the monthly payment to the penny and charges each month's interest in whole pence, as a lender's account does. The last payment clears the few pence that rounding leaves, so it can be a little more or less than the others. The total repaid is every payment added up, and the total interest is the total repaid minus the loan.
Worked example
The fields start with a £300,000 home, a £60,000 deposit, 4.5% a year and a 25-year repayment mortgage. The loan is £240,000.00, which is 80.00% loan to value. The monthly payment is £1,334.00, and the last of the 300 payments is £1,332.96. In total you repay £400,198.96, of which £160,198.96 is interest. Interest-only at the same rate costs £900.00 a month, or £270,000.00 of interest over the term, and the £240,000 is still owed at the end. At main rates, the SDLT on £300,000 in England is £5,000.00. That is nothing on the first £125,000, £2,500 at 2% on the next £125,000 and £2,500 at 5% on the last £50,000. The same price in Scotland costs £4,600.00 in LBTT, or £4,000.00 for a first-time buyer. In Wales the LTT is £4,500.00, which is 6% of the £75,000 above £225,000.
Frequently asked questions
What are the stamp duty rates in England and Northern Ireland?
If the home will be the only residential property you own, SDLT is 0% up to £125,000, 2% on the next £125,000, 5% from £250,001 to £925,000, 10% from £925,001 to £1.5 million and 12% above that. These rates apply from 1 April 2025. If you will own more than one home, the higher rates add 5% to every band, so they run from 5% to 17%. We read both GOV.UK pages on 15 October 2026.
How does first-time buyer relief work?
In England and Northern Ireland you pay no SDLT up to £300,000 and 5% from £300,001 to £500,000, as long as you and everyone buying with you are first-time buyers. Above £500,000 you get no relief at all, and the main rates cover the whole price. In Scotland the relief raises the LBTT nil rate band from £145,000 to £175,000, which saves up to £600. Wales has no first-time buyer relief.
What are the LBTT rates and the ADS in Scotland?
LBTT is 0% up to £145,000, 2% to £250,000, 5% to £325,000, 10% to £750,000 and 12% above, as of 1 April 2021. If you will own more than one home, the Additional Dwelling Supplement adds 8% of the whole price for transactions on or after 5 December 2024. Revenue Scotland charges 6% instead where the contract was entered into on or before 4 December 2024. The calculator uses 8%. The ADS does not apply to a price under £40,000. We read the Revenue Scotland pages on 15 October 2026.
What are the LTT rates in Wales?
For transactions on or after 10 October 2022, LTT is 0% up to £225,000, 6% to £400,000, 7.5% to £750,000, 10% to £1.5 million and 12% above. Buyers who already own a home usually pay the higher residential rates, which run from 5% to 17% and apply from 11 December 2024 unless contracts were exchanged before that date. We read the Welsh Revenue Authority page on 15 October 2026.
When do the rates for an additional home apply?
In all three nations they usually apply when you will own more than one residential property after the purchase and the price is £40,000 or more. Below £40,000 the calculator uses the main rates. If the new home replaces your main home and you sell the old one before or on the day you buy, the main rates usually apply. Couples, trusts and refunds have their own rules in each nation, so check the tax authority's page for your case.
What does the calculator leave out?
It leaves out the non-resident surcharge, purchases by companies and trusts, shared ownership, the rent on a new lease and non-residential or mixed property. On the mortgage side it has no fees, no change of rate after a fixed period and no overpayments.