How much can I borrow on a mortgage?

Every lender calculates affordability differently. On the same income, two lenders can produce maximum loan figures that differ by £100,000 or more. This is why online calculators are a rough guide at best, and why getting a proper broker review can unlock substantially more borrowing than your first high-street quote suggests.

The basic affordability equation

Lenders typically start with an income multiple, historically 4x to 4.5x your annual income, sometimes 5x, occasionally 5.5x or more. They then apply their own affordability calculator, which factors in:

• Basic salary (always 100%).
• Bonus and overtime (often 50%, sometimes 100% for specific professions).
• Self-employed profits or dividends (averaged over 1-3 years).
• Child maintenance, pension contributions, benefits (treated differently by each lender).
• Existing debts, credit cards, car finance, personal loans, student loans.
• Committed outgoings, childcare, private school fees, maintenance payments.
• Stress tests at higher interest rates (currently 6-8% assumption for affordability).

Realistic ranges

For a typical employed applicant with stable income, no major debts, and a reasonable deposit:

• £30,000 single income → typically £120k,£160k maximum borrowing (4-5.3x multiple).
• £60,000 joint income → typically £240k,£330k.
• £100,000 joint income → typically £400k,£550k.
• £200,000 joint income → typically £800k,£1.1m+. HNW territory opens up here.

These are indicative ranges only. The difference between the low and high figure is almost always explained by lender selection, choosing a lender whose specific criteria favour your specific income structure.

What stretches or shrinks your maximum

Stretches your number: qualified professional status (doctor, teacher, nurse, solicitor, etc), minimal debt, strong deposit (15%+), stable long-term employment history, strong credit score, no young children (lower cost-of-living assumptions), no student loans. Shrinks your number: car finance, credit card debt, child maintenance, student loans, temporary or probationary employment, bonus-heavy income, irregular self-employment, existing buy-to-let mortgage commitments.

How a broker makes the difference

Every lender publishes their criteria publicly, but reading their criteria documents tells you roughly 60% of what you need to know. The other 40% comes from placing dozens of cases with each lender every month, knowing how their actual underwriters treat edge cases, which lenders are currently flexible on specific income types, and when a case needs pre-submission dialogue with a lender's BDM. This is what a broker adds.