UK Mortgage Calculator · Practical guide
How Much Is a Mortgage on a £300k House in the UK?
Monthly payments on a £300,000 property, broken down by deposit size and interest rate.
At a glance
The Quick Answer
Buying a £300,000 house with a 10% deposit (£30,000) gives a £270,000 loan. At 5% over 25 years on a repayment basis, that costs about £1,578 per month. On an interest-only basis the same loan costs £1,125 per month, with the £270,000 still owed at the end.
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Results
How Your Deposit Changes the Payment
A bigger deposit shrinks the loan and often unlocks lower interest rates. Here is how the monthly repayment looks at 5% over 25 years for different deposit levels:
| Deposit | Loan Amount | Monthly Repayment | Interest Only |
|---|---|---|---|
| 5% (£15,000) | £285,000 | £1,666 | £1,188 |
| 10% (£30,000) | £270,000 | £1,578 | £1,125 |
| 20% (£60,000) | £240,000 | £1,403 | £1,000 |
How the Interest Rate Moves the Number
On a £270,000 repayment loan over 25 years, each half-point of rate matters: at 4% the payment is about £1,425 per month, at 4.5% about £1,501, at 5% about £1,578, and at 5.5% about £1,658. That is a swing of over £230 a month across a 1.5-point rate range — worth checking against the deals you are actually offered.
Total Cost Over the Term
At 5%, the £270,000 repayment loan totals roughly £473,500 over 25 years, meaning about £203,500 in interest. Enter your own rate and term in the calculator above to see the exact figures for your situation.
Frequently Asked Questions
How much income do I need for a £300k mortgage in the UK?
Most UK lenders offer around 4 to 4.5 times your annual income. For a £270,000 loan that typically means a household income of roughly £60,000 to £67,500, subject to affordability checks.
Is a 5% deposit enough to buy a £300,000 house?
A 5% deposit (£15,000) is the minimum many lenders accept, though 95% loan-to-value deals carry higher rates. A 10% or 20% deposit usually unlocks noticeably cheaper deals.
Does the monthly figure include stamp duty or fees?
No. The calculator shows principal and interest only. Stamp duty, arrangement fees, valuation fees, and legal costs are separate and should be budgeted on top.
What term length is typical for a UK mortgage?
25 years is the traditional standard, but 30 and even 35-year terms are increasingly common among first-time buyers to lower monthly payments, at the cost of more total interest.