Mortgage Affordability Calculator

Work out your borrowing in seconds

Enter your income, deposit and main outgoings in the calculator above and it returns an estimated loan amount, a likely property price range and an indicative monthly repayment. Treat the figure as a starting point for planning, not a formal mortgage offer. A real lender will verify your income with payslips, bank statements and a credit check before committing.

How the affordability calculation works

UK lenders no longer hand out money purely on a fixed multiple of salary. Since the Financial Conduct Authority tightened the rules in 2014, every lender has to test whether you can genuinely afford the repayments, not just today but if interest rates rise. The result is a two-stage assessment, and this calculator follows the same logic.

The first stage is the income multiple. As a rough guide, most lenders cap lending at around four to four-and-a-half times your annual income. For joint applications they usually use the combined household income, sometimes the full total and sometimes the higher earner's salary plus a proportion of the second. So the headline formula is:

Maximum loan ≈ household income × income multiple

The second stage is the affordability stress test. The lender deducts your committed outgoings — credit cards, car finance, personal loans, childcare, student loan and other regular commitments — from your net income, then checks whether the remaining surplus comfortably covers the mortgage payment at a higher "stressed" interest rate. If your outgoings are heavy, you may be offered less than the income multiple alone suggests. If you are debt-free with a big deposit, you may reach the full multiple.

Your deposit matters because it sets your loan-to-value ratio. A 10% deposit means a 90% LTV loan; a 25% deposit means 75% LTV. Lower LTVs unlock cheaper interest rates and make the affordability sums easier to pass, because a cheaper rate means a smaller monthly payment. The property price you can reach is simply your maximum loan plus your deposit.

Remember that affordability is about net, take-home income, not your gross salary. Income tax, National Insurance and pension contributions all reduce what actually lands in your account. If you want to see your real monthly figure, run it through a take-home pay calculator first, then feed that into your budgeting.

Worked example: a first-time buyer couple

Priya and Sam are buying their first home together. Priya earns £34,000 and Sam earns £28,000, so their household income is £62,000. They have saved a £30,000 deposit and have no car finance, but Sam pays £180 a month on a personal loan with two years left.

At a 4.5× multiple, the raw ceiling is £62,000 × 4.5 = £279,000. Add their £30,000 deposit and that points to a property up to around £309,000. But the lender then factors in Sam's £180 monthly loan. Over the assessment that commitment trims the affordable loan by roughly £10,000 to £12,000, so a realistic offer lands closer to £267,000 — a property near £297,000. Clearing that loan before applying would hand most of the borrowing back.

Worked example: a single applicant

Tom is a nurse on £30,000 buying alone. He has a £20,000 deposit and a Plan 2 student loan but no other debt. A cautious lender at 4× offers £120,000; a more generous one at 4.5× offers £135,000. With his deposit, that is a property between £140,000 and £155,000.

His student loan repayment is deducted as a committed outgoing, which shaves a little off the top figure. Because his deposit is around 13% of a £150,000 home, he is at roughly 87% LTV, so he will not qualify for the very cheapest rates — and the higher rate makes the stress test slightly tighter. Saving a little more to cross the 90% or 85% LTV threshold could improve both his rate and his maximum.

What lenders count as income

Basic salary is the foundation, but lenders often include a proportion of reliable extras: guaranteed overtime, regular bonuses, shift allowances and commission, usually averaged over the last two to three months or years. The self-employed are typically assessed on two to three years of accounts or SA302 tax calculations, using net profit or salary-plus-dividends. If your income is irregular, a lender may average it or apply a discount, so your affordable amount can differ from a simple salary multiple.

Costs the headline figure hides

The loan is only part of the picture. Buying a home brings one-off costs that your deposit has to stretch around. The biggest is usually property tax, and it differs by nation: it is Stamp Duty Land Tax in England and Northern Ireland, Land and Buildings Transaction Tax in Scotland, and Land Transaction Tax in Wales. England and Scotland offer first-time buyer relief; Wales does not. Check the bill for your purchase with our stamp duty calculator before you commit, because every pound spent on tax and fees is a pound less for your deposit.

Budget too for valuation and survey fees, conveyancing, mortgage arrangement fees and moving costs. Lenders will also want to see you can absorb these without raiding the deposit you have declared.

How to stretch what you can borrow

• Clear short-term debt first. A £200 monthly commitment can reduce your borrowing by several thousand pounds. Paying off a card or loan before applying often does more than a small pay rise.
• Grow the deposit. Pushing your deposit over the next LTV band (say from 90% to 85%) can lower your rate and ease the affordability test.
• Check your credit file. Register on the electoral roll, correct errors and keep balances low. A stronger file widens the lenders willing to lend at the top of the range.
• Consider the term. A longer mortgage term lowers the monthly payment, which can raise the maximum a lender will offer — though you pay more interest overall.

For a free, impartial overview of the whole process, the government-backed MoneyHelper buying a home guide is a reliable starting point, and the FCA's mortgage pages explain your rights and the affordability rules lenders must follow.

Common mistakes to avoid

• Confusing gross and net. Lenders assess affordability against take-home pay, so a £60,000 salary does not leave £60,000 to spend on a mortgage.
• Forgetting the second applicant's debts. On a joint application, both partners' commitments count, even if only one of you holds them.
• Treating the multiple as a promise. Four-and-a-half times income is a ceiling, not a guarantee. Heavy outgoings, a thin deposit or a patchy credit history can bring it down.
• Ignoring rate rises. The stress test exists because rates move. Borrowing the absolute maximum leaves no cushion if your fixed rate ends and payments climb.
• Overlooking running costs. Council tax, insurance, energy and maintenance are not in the mortgage figure but are very much in your monthly budget.

Once you have a target loan, compare the monthly cost on different terms and rates with our mortgage repayment calculator, and sanity-check the borrowing ceiling against your salary using the how much can I borrow calculator.

These results are estimates for guidance only and are not personal tax or financial advice. A regulated mortgage adviser can give you a decision tailored to your circumstances.

Related calculators

Plan the rest of your purchase with the mortgage calculator for overall costs, the house deposit calculator to set a savings target, and the stamp duty calculator to budget for tax on completion.

The numbers: income multiples lenders actually use

Most UK lenders cap borrowing at 4 to 4.5 times household income, stretching to 5 times for strong applications. Joint applications combine both incomes.

Deposits, credit history and outgoings all move the answer. Free guidance: MoneyHelper mortgage affordability.