Updated 28 August 2026
Mortgage Affordability Calculator UK
Work out how much a UK lender is likely to lend you, and what the property price that buys looks like once your deposit is added. This calculator does what the high street does: applies an income multiple, subtracts your committed credit, then stress-tests the payment at a higher rate to see whether it still holds.
- Single or joint income
- Committed debts deducted
- 8% stress test
- Take-home affordability ratio
How much can I borrow?
What a lender is likely to offer you
Estimated maximum borrowing
£189,000
Property price you could target
£229,000
Loan to value
82.5%
Monthly payment
£0
At the rate you entered
Payment if stressed
£0
At the stress rate
Share of take-home pay
0%
Estimated take-home
£0
Household, per month
Your credit commitments are costing you borrowing power. £0 a month of committed credit reduces your assessable income by £0 a year, which cuts your maximum loan by roughly £0. Clearing a car finance agreement before you apply is often the single fastest way to increase what you can borrow.
How the maximum changes with the income multiple
The same income produces very different outcomes depending on which lender assesses it. This table uses the income you entered above.
| Multiple | Maximum loan | With your deposit | Monthly payment | Availability |
|---|
How UK lenders actually decide what to lend
There are three separate layers, and the headline “4.5 times your salary” is only the middle one.
- The Bank of England’s Financial Policy Committee caps how much of a lender’s new lending can sit at 4.5× loan-to-income or above, capping it at no more than 15% of new residential lending each quarter. This is why higher multiples exist but are rationed rather than advertised.
- The FCA’s conduct rules (MCOB 11.6) require lenders to verify income, assess your committed expenditure, and apply a forward-looking interest rate stress test.
- The lender’s own risk model then produces a specific multiple, stress margin and expenditure benchmark. Two lenders looking at the same payslip can land more than £80,000 apart.
Why the calculator asks for committed credit. Lenders do not look at your income in isolation. They deduct what is already promised to someone else. A £300 a month car finance payment removes £3,600 a year from assessable income, which at 4.5× is roughly £16,200 less to spend on a house.
What increases your maximum
- A longer term. Moving from 25 to 35 years lowers the monthly payment enough to pass more stress tests, at the cost of far more lifetime interest. Check the difference on the main mortgage calculator.
- A bigger deposit. This does not raise the income multiple, but a lower LTV unlocks cheaper rates, which lowers the stressed payment.
- Clearing short-term credit. Especially agreements ending within six months, since some lenders ignore those, most do not.
- Evidenced variable pay. Two years of consistent bonus or overtime on payslips is usually counted at 50% to 100%.
- Choosing the right lender. This is what a whole-of-market broker is genuinely worth: knowing which lender treats your income shape most generously.
What reduces it
- Dependants, because each child typically reduces assessable income through the expenditure benchmark.
- Recent missed payments or defaults on your credit file.
- Self-employment with under two years of accounts, or a falling second-year profit.
- A flat above commercial premises, short lease, or non-standard construction, a property-side limit rather than an income one.
Affordability questions, answered
Is 4.5 times salary still the limit in 2026?
It is the default, not a cap. The regulatory limit applies to the proportion of a lender’s book above 4.5×, not to individual applications. In 2026 Halifax, Nationwide, Barclays and others routinely write 5.5× for applicants with strong income and low LTV, and NatWest offers up to 6.5× on joint applications with combined income above £150,000.
Does a student loan affect my mortgage affordability?
Not as a debt on your credit file, because student loans do not appear there and do not count as committed credit. They do reduce your net pay, and most lenders capture that through the affordability assessment rather than the income multiple. The practical effect is usually modest compared with car finance or credit card balances.
How much do lenders count of my bonus or overtime?
Typically 50% to 100%, depending on the lender and how consistent it is. Two years of payslips showing a regular bonus gets counted most generously. A single exceptional year usually gets averaged down or discounted heavily. Enter only what you can evidence.
What is a mortgage stress test?
A check that you could still afford the payment if rates rose. The lender recalculates your monthly payment at a higher rate, commonly 6% to 8% in 2026 or your product rate plus a margin, and confirms it still fits within your assessed budget. It is why you can be refused at a payment you are visibly already paying in rent.
Should I get a decision in principle first?
Yes, before you view seriously. A decision in principle takes minutes, usually uses a soft credit search, and gives estate agents confidence that your offer is real. It is not a mortgage offer and does not commit the lender, but in a competitive market a seller will often prefer a buyer who has one.
Next step: once you know your budget, run the real numbers on the mortgage repayment calculator, then check the one-off tax bill with the stamp duty calculator. Read the full explainer: how much can I borrow for a mortgage?