Mortgage affordability calculator: see how much 58 UK lenders would offer you.

UK mortgage affordability is the maximum amount a lender will let you borrow, based on your income, monthly outgoings, and the lender’s own stress test of what you could still pay if interest rates went up. It’s the “how much can I borrow” figure that drives every mortgage decision — and crucially, it varies by lender. The same applicant can be offered £240,000 by one bank and £310,000 by another on identical inputs.

The two main levers are the income multiple (typically 4 to 4.5 times annual income, up to 5x or 5.5x for higher earners) and the stress rate the lender applies to test whether you could still afford the payment if rates rose. Different lenders apply different rules to bonus income, overtime, commission, self-employment profits, and pension contributions — and those rule differences are what produce the £40-80k spread between offers.

Beyond the income side, lenders also assess your committed expenditure (loans, credit-card debt, school fees, child maintenance), your credit history, and the property itself. A handful of factors — probation period employment, a foreign-currency salary, a flat above commercial premises, a recent CCJ — narrow your lender pool dramatically. We’ve built dedicated tools so you can see who accepts your situation in those edge cases.

The point of running our calculator before applying is simple: every full mortgage application leaves a hard credit search. Applying to a lender that would have declined you anyway costs a small ding on your credit file — and three or four of those compound. We check the lender criteria and affordability calculations without ever touching your credit file, so you can focus your application on lenders likely to say yes.

As a rough rule of thumb, expect 4 to 4.5 times your annual gross income on a standard residential mortgage with a 10-15% deposit. Higher earners and clients with larger deposits often access 5x to 5.5x. Joint applicants combine incomes, which usually multiplies up rather than averages.

Quick reference at standard 4.5x multiple, single applicant:

Real-world figures depend heavily on your outgoings, deposit, credit profile, and whether you have bonus or commission income. The calculator runs your actual figures through each lender’s own calculation, giving you a more accurate picture for your circumstances.

For each of 58 UK lenders, we run your inputs (income, employment type, deposit, outgoings, credit profile, property type) through that lender’s real affordability model — usually their own published API or calculator, supplemented by hand-coded criteria from their broker portal where the API doesn’t exist. You see a per-lender maximum borrowing figure, a flag for any lender that explicitly declines your situation, and a side-by-side comparison.

The full 58-lender panel — including specialists (Kensington, Pepper, Bluestone, Precise, Vida, Together, etc.) — is completely free right now, and buy-to-let is covered too across 22 specialist BTL lenders.

We’re an independent information tool, not an FCA-authorised broker. The calculator tells you which lenders are open to you and how much they’d lend; your broker remains the right person to confirm and apply. See our methodology for the detail on how each calculation is built.