Working out how much you can borrow for a mortgage is the first step in any property purchase. Most UK lenders use a combination of income multiples and affordability assessments to determine the maximum loan they'll offer. Here's exactly how it works in 2026 — with worked examples for different salary levels.
The Income Multiple Rule
The most common way lenders calculate your maximum mortgage is by multiplying your annual gross salary by a set figure — typically between 4x and 4.5x. Some lenders will go up to 5x or even 5.5x for higher earners, certain professions (doctors, lawyers, accountants), or borrowers with large deposits.
| Annual Income | At 4× income | At 4.5× income | At 5× income |
|---|---|---|---|
| £25,000 | £100,000 | £112,500 | £125,000 |
| £35,000 | £140,000 | £157,500 | £175,000 |
| £50,000 | £200,000 | £225,000 | £250,000 |
| £75,000 | £300,000 | £337,500 | £375,000 |
| £100,000 | £400,000 | £450,000 | £500,000 |
| £50k + £30k (joint) | £320,000 | £360,000 | £400,000 |
If you're buying with a partner, most lenders will combine both incomes to calculate the maximum loan. A couple earning £50,000 and £30,000 respectively would have a combined income of £80,000 — giving a maximum of £360,000 at 4.5x.
Affordability Assessments
Income multiples are just the starting point. Lenders also carry out a full affordability assessment, looking at your monthly outgoings including:
- Existing loan and credit card repayments
- Car finance
- Childcare costs
- Other regular commitments
High monthly outgoings can significantly reduce how much you're able to borrow, even if your income-based calculation is generous. Lenders will also stress-test your affordability at higher interest rates to ensure you could still afford repayments if rates rise.
Calculate your maximum mortgage
Use our free mortgage affordability calculator to see your maximum borrowing power based on your income, deposit and outgoings.
🔑 Mortgage Affordability CalculatorHow Much Deposit Do You Need?
Your deposit size determines your Loan to Value (LTV) ratio — and this directly affects the interest rates available to you.
| Deposit | LTV | Rate availability |
|---|---|---|
| 5% | 95% | Limited lenders, highest rates |
| 10% | 90% | More lenders, competitive rates |
| 25% | 75% | Wide choice, good rates |
| 40%+ | 60% or less | Best rates available |
What About Self-Employed Borrowers?
Self-employed borrowers can get mortgages but lenders typically require at least 2–3 years of accounts or SA302 tax returns. Most lenders use your average profit over the past 2–3 years rather than your most recent year's income. If your income has been rising, this can result in a lower maximum loan than you might expect.
Tips to Maximise Your Mortgage
- Pay down debts — reducing credit card balances and loans improves affordability
- Check your credit file — errors can reduce your options, and you can fix them for free
- Save a bigger deposit — moving from 5% to 10% opens up significantly more lenders
- Use a mortgage broker — they can access deals not available direct and match you to the right lender
- Avoid new credit applications before applying — hard searches affect your credit score
Frequently Asked Questions
This article is for general information only and does not constitute financial advice. Always speak to a qualified mortgage adviser before making any decisions.