Mortgage Affordability Calculator UK 2025/26
Find out how much you can borrow, estimate your monthly payments and see how your mortgage holds up under the lender stress test. Enter your income, deposit and preferred rate to get started.
Enter your income and deposit, then click Calculate to see your borrowing power.
Income multiple guide — how much can you borrow?
| Annual income | Standard (4.5×) | Enhanced (5×) | Enhanced (5.5×) |
|---|---|---|---|
| £30,000 | £135,000 | — | — |
| £40,000 | £180,000 | — | — |
| £50,000 | £225,000 | — | — |
| £60,000 | £270,000 | — | — |
| £75,000 | £337,500 | £375,000 | — |
| £100,000 | £450,000 | £500,000 | £550,000 |
| £150,000 | £675,000 | £750,000 | £825,000 |
Enhanced multiples (5× and 5.5×) are offered by some lenders for higher earners. Availability depends on lender criteria, deposit size and credit profile.
How Mortgage Affordability is Calculated in the UK
UK lenders use two overlapping tests to decide how much you can borrow. The first is the income multiple — a simple cap of 4.5 times your gross annual income, or combined income for joint applications. This sets the ceiling on how large a mortgage a lender will offer regardless of how affordable the monthly payments appear.
The second is the affordability assessment, which looks at your income, regular outgoings, committed expenditure (debts, credit cards, childcare) and lifestyle spending to determine whether you can comfortably meet repayments both now and if interest rates rise. Most lenders will lend up to the lower of these two results.
What is an Income Multiple?
An income multiple is the ratio of mortgage size to gross annual income. The Bank of England introduced a 15% cap rule in 2014 preventing lenders from issuing more than 15% of new mortgages at income multiples above 4.5×. In practice, the standard cap for most borrowers is 4.5×, meaning a single applicant earning £40,000 can borrow a maximum of £180,000.
Some lenders will stretch to 5× or even 5.5× for high earners (typically those on £75,000 or more), certain professions such as doctors and solicitors, or where the overall loan-to-value is low. A mortgage broker can identify which lenders are most likely to offer higher multiples based on your specific profile.
What is LTV (Loan-to-Value)?
Loan-to-value (LTV) is the mortgage amount expressed as a percentage of the property's value. A £180,000 mortgage on a £200,000 property has an LTV of 90%. LTV directly affects the interest rates available to you: the lower your LTV, the less risk the lender takes on and the better the rate you can access.
The most widely available mortgages are at 60%, 75%, 80%, 85%, 90% and 95% LTV. The Help to Buy and 95% mortgage guarantee schemes have made 95% LTV mortgages more accessible since 2021, though rates at the top LTV tiers are significantly higher. A 5% deposit (95% LTV) is the minimum accepted by most lenders.
How Lenders Stress Test Mortgages
Lenders are required to check that borrowers could still afford their mortgage if interest rates were to rise. This is called the stress test. Since the Bank of England's withdrawal of the mandatory 3% stress test floor in 2022, individual lenders now apply their own stressed rates — typically 1–3% above the initial product rate. This calculator applies a 3% stress test above the rate you enter, which remains a widely used industry benchmark.
For example, if you apply for a mortgage at 4.5%, the lender may assess affordability at 7.5%. The verdict shown by this calculator — green, amber, or red — is based on whether the stressed monthly payment stays within 35% of your gross monthly income, which is the threshold commonly used in lender affordability models.
Frequently Asked Questions
How much can I borrow on a £50,000 salary?
On a £50,000 salary, the standard 4.5× income multiple allows you to borrow up to £225,000. With a £25,000 deposit (10% of a £250,000 property), you could target a purchase price of around £250,000 at 90% LTV. Some lenders may offer up to £250,000 (5×) depending on your outgoings, credit profile and the lender's own criteria. The actual amount offered will depend on the full affordability assessment, not just the income multiple.
Can I get a mortgage with a 5% deposit?
Yes. A 5% deposit gives you a 95% LTV mortgage, which most major high-street lenders now offer. Rates at 95% LTV are noticeably higher than at 90% or 85%, so saving an extra few percent can meaningfully reduce your monthly payments and total interest paid. First-time buyers in England also benefit from the government's mortgage guarantee scheme, which has helped lenders offer more competitive 95% LTV products.
What is the mortgage stress test?
The mortgage stress test checks whether you could still afford your mortgage repayments if interest rates rose sharply from your initial rate. Lenders typically add 1–3% to your product rate and assess whether the resulting monthly payment would exceed an affordable proportion of your income — usually around 35%. This is designed to protect borrowers from over-extending on the assumption that today's rates will last for the full mortgage term.
Do debts affect mortgage affordability?
Yes, significantly. Monthly debt commitments — including car finance, personal loans, credit card minimum payments and hire purchase agreements — are deducted from your disposable income before the lender assesses what mortgage payment you can afford. A £500/month car finance payment on a £50,000 salary can reduce your maximum borrowing by £30,000–£40,000 depending on the lender's model. Clearing debts before applying for a mortgage is one of the most effective ways to increase your borrowing power.
How does joint income affect borrowing?
For a joint mortgage, lenders combine both applicants' incomes and apply the income multiple to the total. Two applicants earning £30,000 each have a combined income of £60,000 and can borrow up to £270,000 at the standard 4.5× multiple — considerably more than either could borrow individually. Both applicants' credit histories, existing debts and expenditure are assessed in the affordability check. Having one applicant with significant debts or a poor credit score can reduce the amount available despite a strong combined income.