Mortgage affordability: how much can you actually borrow?
Most lenders cap borrowing at 4–4.5× your income - but income is only half the story. Here’s how affordability really works, what lenders check, and how to work out your own number.
2 min read · Updated 7 August 2026 · By Dwellmark Editorial
The rule of thumb is that UK lenders will lend you around 4 to 4.5 times your annual income - £180,000–£202,500 on a £45,000 salary. Some lenders stretch to 5× or even 5.5× for high earners or low outgoings, but that’s the exception, not the norm.
A quick look at the numbers
| Household income | 4.5× borrowing | With 10% deposit | Max price |
|---|---|---|---|
| £35,000 | £157,500 | £17,500 | £175,000 |
| £45,000 | £202,500 | £22,500 | £225,000 |
| £60,000 | £270,000 | £30,000 | £300,000 |
| £80,000 (joint) | £360,000 | £40,000 | £400,000 |
Income is only half the story
Lenders run a detailed affordability assessment, not just a multiple:
- Outgoings: credit commitments (loans, cards, car finance), childcare, and your spending pattern from 3–6 months of bank statements
- Stress test: they check you could still afford the mortgage if interest rates rose around 3 percentage points above today’s
- Credit history: missed payments, defaults and court judgments reduce what you can borrow - and some lenders won’t lend at all
- Deposit size: a bigger deposit (lower LTV) means a smaller loan, which passes affordability more easily
- Employment: permanent employment is easiest; contractors and self-employed applicants may need 1–3 years of accounts
The 4.5× rule vs your real number
The multiple is a starting point. Two people on identical salaries can be offered very different amounts - one with a car loan, credit card debt and nursery fees will be offered less than one with minimal outgoings. This is why a mortgage in principle (AIP) is so valuable: it gives you your number before you start viewing homes.
Try the calculator
Mortgage affordability calculator
Full page ↗You could borrow
£202,500
Max property price
£227,500
Estimate only - a lender’s affordability assessment determines the real offer. Lenders assess outgoings, credit history and stress-test rates — a mortgage in principle gives you the real number.
Estimate how much you could borrow based on your household income, using the standard 4–4.5× income multiple lenders apply.
How to improve what you can borrow
- Clear expensive debt - paying off a car loan or credit card is usually the fastest win
- Cut regular spending for 3–6 months before applying (lenders review statements)
- Build your deposit past a band boundary (e.g. 10% → 15%) to unlock cheaper rates
- Check your credit report for errors before you apply (free via the main agencies)
- Fix errors early - mistakes on credit files are more common than people think
Source: Financial Conduct Authority - understanding mortgage affordability — Guidance checked August 2026
The full buying processWhere the mortgage fits in the overall timeline.Stamp Duty calculatorFactor the tax into your total budget.
Sources
- Financial Conduct Authority - understanding mortgage affordability — Guidance checked August 2026
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