Mortgage affordability calculator
This gives a range rather than a number, because that is honestly all anyone can give you without running a credit check and applying their own lending criteria. It is a useful starting point for planning, and it is not a decision in principle.
Your situation
Stress test
Lenders check the mortgage would still be affordable if rates rose. This does the same.
Indicative range
You might borrow around
£0
How this is worked out
Most UK lenders start from a multiple of income, then adjust it for your circumstances. The range here uses three multiples to show how much that judgement varies between lenders rather than pretending there is one right answer.
adjusted income = total income − (monthly commitments × 12)
cautious = adjusted income × 4.0
typical = adjusted income × 4.5
a stretch = adjusted income × 5.0
property price = borrowing + deposit
Existing credit commitments are deducted from income before the multiple is applied, which is roughly how lenders treat them. Paying off a car finance agreement before applying can therefore increase what you can borrow by considerably more than the balance you cleared.
Why the range is so wide
Lending is not a formula. Two lenders looking at identical figures routinely differ by tens of thousands of pounds, because they weight things differently: how secure your employment looks, whether income includes bonuses or overtime, your credit history, how many dependants you have, what you actually spend each month, and how large your deposit is. A bigger deposit often unlocks both a better rate and a more generous multiple.
The stress test
Lenders do not only check you can afford today's rate. They check the mortgage would still be affordable if rates rose substantially, which is why the calculation here applies a higher rate than you would expect to pay. If the stressed payment takes more than about a third of take-home pay, that is usually the point where lenders start becoming uncomfortable, and it is worth taking seriously as a personal limit too, not just a lending hurdle.
What this ignores
- Your credit history and score, which can change everything and which no calculator can see.
- The nature of your income. Self-employment, bonuses, commission, contract work and benefits are all treated differently by different lenders.
- Dependants and childcare, which reduce borrowing capacity with most lenders.
- Your actual monthly spending, which lenders review through bank statements.
- The property itself. Flats above shops, non-standard construction and short leases can all restrict lending regardless of your income.
- Whether a lender will offer the term you want, particularly if the mortgage would run past retirement age.
Before you rely on this
The single most useful next step is a decision in principle from a lender or a conversation with a whole-of-market mortgage broker. Both are usually free to obtain, both account for the things above that this page cannot, and a decision in principle carries weight with estate agents that a calculator result does not. It is also worth checking your credit file first, since errors on it are common and take time to correct.