How much can I actually borrow?
Usually around four and a half times your income. That's the figure most calculators give you.
Calculators quote you an income multiple. Lenders run an affordability model. The gap between them is where offers fall over.
The income multiple is a ceiling, not a promise. Lenders also work out what you can afford each month. They start from your take-home pay, take off your regular commitments and an estimate of everyday spending, then check the payment would still be manageable if your rate went up. Whichever of the two numbers is lower is the one you're offered.
For someone on a modest income, that monthly check is often the one that bites. Two people on the same salary can be offered quite different amounts, because a car loan, a student loan repayment or childcare costs all come out before the lender looks at what's left.
Lending at four and a half times income or more is also limited across the market as a whole. The regulators aim to keep it to 15% of new mortgages. Since October 2026, individual lenders have more room to go above that share, as long as the total across all lenders stays within it. So some lenders will stretch further than others.
Our calculator shows you both numbers side by side, and which one is holding you back. It's an estimate, not a decision in principle.
Where this information comes from
Across all lenders, mortgages at 4.5 times income or more are kept to 15% of new lending. Since October 2026 that's measured across the market, so an individual lender can lend more of these if the total stays within the limit.
Source: PRA and FCA, high loan to income lending, PS19/26 (October 2026). Checked 28 October 2026.
Unless the rate is fixed for five years or more, lenders must consider likely interest rates over the first five years and assume they rise by at least one percentage point.
Source: FCA Handbook, MCOB 11.6.18. Checked 28 October 2026.
General information, not advice about your circumstances. Rules and rates change; this page was last checked 28 October 2026. Spotted an error? Tell us.