How Much Can I Actually Borrow?
Everyone asks this before they've even started looking, and everyone gets a slightly different answer depending on which calculator they typed it into at 11pm. So let's actually clear it up.
The number everyone quotes, and why it's not the whole story
Ask anyone who's bought a house and they'll tell you: "four and a half times your salary." It's not wrong - MoneyHelper, the government's own free guidance service, quotes the same figure as the standard cap most lenders work to. But it's a starting point, not a ceiling, and it's definitely not the number every lender will actually offer you.
Here's a more cohesive answer: most mainstream lenders sit somewhere between 4 and 4.5 times your income, but plenty go higher depending on who you are and what you earn. Some will stretch to 5x for higher earners and some have offered up to 5.5x for first-time buyers who meet specific criteria. And if you're in a profession like medicine, dentistry, law or accountancy, specialist lenders will sometimes go to 5.5x or even 6x, on the basis that your income is stable and likely to keep climbing.
None of this is a lender being generous out of the kindness of their heart. It's risk modelling. But it's exactly why two people earning the same salary can walk away with very different maximum mortgages - and why "I got told 4.5x" from a mate isn't always the ceiling for you.
The stress test: The bit nobody explains properly
Every lender runs what's called an affordability stress test: they check whether you could still afford your repayments if interest rates went up, not just at the rate you're being offered today. Until August 2022, the Bank of England required lenders to test against a specific 3% margin above their standard variable rate. That requirement was withdrawn - lenders now set their own stress margin, and most currently test at somewhere around 7-9%, well above the base rate itself (3.75% as of September 2026).
What that means practically: your maximum borrowing isn't calculated on today's mortgage rate. It's calculated on a noticeably higher rate that you're not actually going to pay, as a buffer. It feels counterintuitive the first time someone explains it, but it's the reason a rate cut doesn't automatically mean everyone can suddenly borrow more.
What quietly drags your number down
Income gets all the attention, but outgoings do most of the damage to your maximum. Lenders look hard at:
Existing credit commitments - credit cards, car finance, loans, even 0% "buy now, pay later" balances now increasingly show up and get factored in
Dependents - the number of children or other dependents you support reduces disposable income in the calculation
Subscriptions and regular spending - some lenders now dig into bank statements rather than just self-declared figures
Employment type - self-employed and contract income is assessed differently, usually over 2-3 years of accounts rather than a single payslip
Two people on identical £50,000 salaries can walk away with genuinely different maximum mortgages once all of this is factored in. It's not a flaw in the system - it's the system working as designed.
Why every online calculator gives you a different answer
This is the bit that drives people slightly mad. Plug your numbers into five different calculators and you'll get five different figures, because every lender's underwriting model weighs income, debt, and dependents slightly differently. MoneyHelper's own affordability calculator is a genuinely good, free, impartial starting point precisely because it isn't trying to sell you anything - but even it will tell you the real number depends on the actual lender you apply to.
There's no single "correct" answer sitting out there. There's only the answer a specific lender gives you once they've seen your actual numbers.
Buying with someone else
If you're buying jointly, most lenders use combined income for the multiple, then apply the same affordability and stress checks against your joint outgoings. It's not simply "add both salaries and multiply" - one applicant's existing debt or dependents affects the joint figure just as much as it would if they were applying alone.
So what should you actually do with this?
Truthfully, this is where we genuinely believe we can make a difference. We're not tied to one lender's model, so rather than you running the same numbers through six different calculators and getting six different answers, we can tell you upfront which lenders are likely to offer you the most for your specific situation, before you've fallen for a flat you can't actually get approved for.
If you are interested in learning more, you can BOOK A CALL here.
