Z

United Kingdom Mortgage Calculator

Estimate monthly repayments on a UK repayment mortgage in GBP, and see what happens when a two- or five-year fixed deal reverts to the lender SVR.

Runs in your browser — files never leave your device

Monthly payment
£1,798.65
Total interest
£347,514.57
Total paid
£647,514.57

How it works

The United Kingdom edition of the mortgage calculator. It works out the monthly repayment on a capital-and-interest repayment mortgage — the standard residential product — from the amount borrowed, the rate and the term. Enter the amount you are borrowing, not the property price: a £300,000 purchase with a £60,000 deposit is a £240,000 mortgage. Interest-only mortgages work differently and are not modelled here.

The maths is repayment = P × r × (1 + r)ⁿ / ((1 + r)ⁿ − 1), with P the amount borrowed, r the monthly rate (annual rate ÷ 12 ÷ 100) and n the number of monthly repayments — 300 for a 25-year term. Because interest is charged on the outstanding balance, the early years clear very little capital.

Worked example at a hypothetical 4.75%: £240,000 over 25 years gives £1,368.28 a month. Over a five-year fixed deal you would pay £82,096.80 in total, of which only £28,264.89 comes off the capital and £53,831.91 is interest, leaving £211,735.11 outstanding. If that balance then reverted to a hypothetical 6.75% standard variable rate for the remaining 20 years, the repayment would jump to £1,609.96 — £241.68 a month more for exactly the same debt.

That is the key UK caveat: a residential mortgage here is normally a two- or five-year fixed deal that reverts to the lender’s standard variable rate, sitting inside a 25 to 35 year term. So the “total interest” figure — £170,484.50 in the example — assumes one rate for 25 years, which almost nobody actually pays. Most borrowers remortgage at each deal end onto a new fixed rate, which is why the repayment at reversion matters more than the lifetime total. Lenders also stress-test affordability at a rate higher than the one you are offered, so the amount you can borrow is set by their assessment, not by whichever repayment looks manageable on a calculator.

Costs outside this figure: Stamp Duty Land Tax on the purchase, where rates, bands and reliefs differ by nation and by whether you are a first-time buyer or buying an additional property, plus arrangement and valuation fees, conveyancing, buildings insurance, and any ground rent or service charge on a leasehold property. Overpayments are not modelled either, although most deals allow some each year and they cut interest in every later month. These are estimates for planning — confirm the figures with your lender or a qualified mortgage adviser before committing.

Other regions: United States, Canada, Australia.

Frequently asked questions

What happens when my fixed deal ends?
Unless you remortgage, the balance moves onto the lender’s standard variable rate, which is usually higher. In the worked example a £211,735.11 balance reverting from 4.75% to a hypothetical 6.75% over the remaining 20 years takes the repayment from £1,368.28 to £1,609.96 — £241.68 a month more.
Why is the total interest figure not realistic for a UK mortgage?
Because it assumes a single rate for the entire term. UK deals are typically fixed for two or five years inside a 25 to 35 year term, so you will pass through several rates and probably several lenders. Use the total as a comparison between scenarios, not as a forecast of what you will pay.
Should I enter the property price or the mortgage amount?
The mortgage amount — the price minus your deposit. A £300,000 property with a £60,000 deposit means entering £240,000. Entering the full price inflates both the repayment and the interest.
Does this include Stamp Duty Land Tax?
No. Stamp Duty is a one-off tax on the purchase rather than part of the monthly repayment, and the rates, bands and reliefs vary by nation and by buyer status — first-time buyer, mover or additional property. Check the current bands for your situation and budget for it separately.
Can I borrow whatever this calculator says I can afford?
No. Lenders assess your income and outgoings and stress-test the repayment at a rate above the one offered, so the maximum loan comes from their affordability model. The repayment here is a budgeting figure, not an indication of what will be approved.
Is it right for an interest-only mortgage?
No — this calculates a capital-and-interest repayment. On interest-only you pay just the interest each month and the full capital is still owed at the end, so the monthly cost is lower but the balance never falls.
What about overpayments?
They are not modelled, but they help: because interest is charged on the outstanding balance, an overpayment reduces interest in every remaining month. Check the annual overpayment allowance on your deal, since exceeding it can trigger an early repayment charge.

Related tools