UK Mortgage Affordability Calculator — Can You Really Afford That House?

Question 1

How much mortgage can I afford on my salary?

Accepted Answer

Most UK lenders cap borrowing at 4–4.5× your annual gross income. But what the bank will lend you and what you can comfortably afford are different things. This calculator will factor in your actual take-home pay, monthly outgoings, and stress-tested repayments to give you a realistic answer.

Question 2

What is a mortgage stress test?

Accepted Answer

A stress test checks whether you could still afford your mortgage if interest rates rose. UK lenders typically stress test at 1–2% above their standard variable rate. This calculator applies similar stress tests so you can see the impact before you commit.

Question 3

Does the calculator include stamp duty?

Accepted Answer

Yes. The calculator uses current HMRC stamp duty land tax (SDLT) rates for England and Northern Ireland, including first-time buyer relief where applicable. Scottish LBTT and Welsh LTT are not currently supported.

Question 4

Can I use this calculator for buy-to-let?

Accepted Answer

Not yet. Buy-to-let mortgages use different affordability criteria based on rental income rather than personal salary. This calculator is designed for residential purchases where you plan to live in the property.

Question 5

How does the calculator work for self-employed applicants?

Accepted Answer

If you know your annual income (typically the average of your last 2–3 years’ SA302 figures), you can enter it as your gross salary. However, lenders assess self-employed applicants differently, and some accept lower income multiples. The result gives a reasonable starting point, not a lender-specific answer.

Question 6

What costs are included beyond the mortgage?

Accepted Answer

The calculator factors in stamp duty, estimated council tax, and buildings insurance. It does not include solicitor fees, survey costs, removal expenses, or ongoing maintenance. These vary widely and are better budgeted separately.

Question 7

Does this work for shared ownership or Help to Buy?

Accepted Answer

No. Shared ownership and Help to Buy schemes have their own affordability rules and equity loan structures. This calculator assumes a standard residential mortgage with a deposit and no equity loan.

Question 8

Can I afford a house on my own?

Accepted Answer

Many single buyers successfully get mortgages. The key factors are your income, deposit size, existing debts, and monthly outgoings. Enter your figures as a sole applicant to see where you stand. The calculator shows whether repayments are comfortable relative to your take-home pay.

Question 9

How accurate is this compared to a lender’s calculation?

Accepted Answer

Each lender uses its own affordability model, which considers factors like credit score, employment type, and committed expenditure. This calculator gives you a realistic ballpark based on income multiples and stress-tested repayments. It is not a mortgage offer and does not replace a Decision in Principle.

UK Mortgage Affordability Calculator — Can You Really Afford That House?

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Methodology

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