PropertyStamp Duty Mortgage Affordability Rent vs Buy

Tax year 2026/27 · Rest of UK · annual

Mortgage Affordability Calculator

How much you can borrow on your income and deposit.

Tax year

Region

Schedule

Your details

Annual income

Deposit saved

Monthly debt repayments

Credit cards, loans, car financeIncome multipleMost lenders use 4x–5x

Estimated max borrowing

£202,500

4.50x combined income of £45,000

What that buys

Max mortgage	£202,500
Plus your deposit	£30,000
Max property price	£232,500
Loan-to-value	87.1%

Interactive scenarios

Tax and deductions, your way

Tax year

Region

Pay schedule

Salary £45,000

Net (monthly)

£2,806

Income tax (monthly)

£541

NI (monthly)

£216

Effective rate

20.2%

Modelled on a 5% pension. Showing monthly figures, rest of UK, tax year 2026/27.

The full guide

Everything worth knowing about Affordability

Worked examples with real figures, the rules underneath the number, and the traps that catch people out.

Mortgage Affordability Calculator: how much a lender will let you borrow

The mortgage affordability calculator estimates the largest loan a UK lender is likely to offer you: your income multiplied by a lending multiple, reduced for the debts you already pay each month, with your deposit added on top to give a maximum property price. On a £45,000 salary at the typical 4.5 times multiple, the borrowing figure is £202,500, and a £30,000 deposit lifts the ceiling to a £232,500 home.

Treat that number as the ceiling the arithmetic allows, not as a promise. Behind it every lender runs a fuller assessment of your spending, your commitments and your ability to pay if rates rise, and the sections below show where applicants gain or lose ground in that assessment.

The multiple is the headline. The assessment is the decision.

A ceiling, not a promise

The income multiple sets the largest loan the headline maths allows. Your actual offer comes out of the lender's full affordability assessment, and it can land well below the ceiling when commitments are heavy.

Income multiples: the headline cap on borrowing

Most high street lenders cap borrowing at around 4 to 4.5 times your income, and that cap is the first filter your application meets. On £45,000 the range runs from £180,000 at four times to £202,500 at 4.5 times, and a lender willing to stretch to five times takes the same salary to £225,000.

Half a point of multiple is worth £22,500 on that salary, which is why two lenders can quote the same applicant figures a whole street apart in price. Higher multiples exist, but lenders ration them: larger incomes, professional occupations, a low loan to value and a clean credit record all strengthen the case, and the calculator above lets you test any multiple from 1 to 6 to see where your own ceiling sits.

Joint applications are assessed on combined income. Two salaries of £45,000 and £30,000 give £75,000, and 4.5 times that is £337,500 before any deduction for debts. A partner's income counts in full inside the multiple, and so do their commitments, which is why the debt section below matters twice on a joint application.

Variable pay counts for less than salary. Many lenders take only part of overtime, commission and bonuses into the income figure, or average them over two or three years, so two applicants with identical total pay can be offered different ceilings depending on how their pay is built.

What counts as income is a lender decision too. Basic salary counts in full from the first payslip. Regular allowances and a second job often count once they have a track record behind them, while income from benefits, lodgers or a new side business is ignored by many mainstream lenders entirely. Before you rely on a figure, it has to be the kind of income a lender will write down, not just money that reaches your account.

Affordability

Income in, borrowing out

Income

£45,000

Borrowing at 4.5× income

£202,500

Max price with a £30,000 deposit

£232,500

The stress test: could you still pay if rates rose?

Passing the multiple only earns you the full assessment, and at its centre sits a stress test: the lender checks that the payment still fits your budget at a rate well above the one you would actually pay. A loan of £202,500 over 25 years costs £1,126 a month at 4.5%. At a stressed 7.5% the same loan would cost £1,496, and the lender wants to see that £371 gap covered by income left over after essentials.

The assessment prices your life as well as your loan. Rent or current mortgage payments, council tax, utilities, food, travel, childcare and insurance all come off your income before the lender decides what is spare, and smaller regular commitments count too when they appear on your statements.

This is where applications that clear the multiple still shrink. A borrower can pass at 4.5 times on paper and be offered less because the budget left after committed spending cannot carry the stressed payment, and no appeal to the headline multiple changes that arithmetic.

The term you choose feeds straight into this test, because a longer term lowers the payment being stressed. The £202,500 loan above costs £1,126 a month over 25 years and £958 a month over 35 years at the same 4.5% rate. Stretching the term can carry a borderline budget through the assessment, and the price of doing it is more interest across the life of the loan, so it buys approval rather than cheapness.

Committed debts: every £100 a month costs £3,600 of borrowing

Existing debts cut your borrowing hard, and the calculator applies the reduction openly: it annualises your monthly repayments and deducts three years of them from the loan. Every £100 a month of committed debt therefore removes £3,600 of borrowing, so a £250 a month car payment takes £9,000 off the maximum loan.

Run the joint example through it. Combined income of £75,000 at 4.5 times gives £337,500, and a £250 a month car finance payment pulls that down to £328,500 before the deposit goes on. The car costs its monthly payment, and then it costs £9,000 of house.

Clearing a commitment before you apply is the fastest legitimate way to raise your ceiling. Paying off a card or loan removes its full monthly figure from the assessment, and the gain in borrowing capacity routinely beats saving the same cash as extra deposit, because a deposit only adds pound for pound while a debt was deducting thirty six times its monthly size each year it ran.

Credit cards deserve a word of their own. A balance you clear in full every month still shows on your statements, and many lenders assess a card on its balance rather than on the payment you actually make. A large balance held at the moment you apply can therefore cost borrowing capacity out of all proportion to the interest you pay on it, which is usually none.

Worked example: £45,000 of income, step by step

Start with a single applicant on £45,000, no debts and a £30,000 deposit. At 4.5 times income the calculator gives £202,500 of borrowing, the deposit takes the maximum price to £232,500, and the loan to value lands at 87.1%, inside the band where mainstream rates apply.

Now add a partner on £30,000 and a £250 a month car payment. Combined income of £75,000 lifts the raw figure to £337,500, the debt deduction removes £9,000, and the same £30,000 deposit produces a maximum price of £358,500. Two changes, income and debt, moved the ceiling by £126,000 between them. Neither borrower did anything exotic; they simply presented the assessment with more income and less commitment.

Your deposit: the other half of the ceiling

The deposit decides the price your borrowing can reach and the rate you will pay for it. Borrowing is capped by income, and the deposit stacks straight on top: £202,500 of borrowing plus £30,000 reaches a £232,500 property, and every further pound saved is a pound of price or a pound less debt.

The same deposit also sets your loan to value, and lenders price in bands. The £232,500 purchase above runs at 87.1% loan to value. Put 25% down on that same home, a deposit of £58,125, and the loan falls to £174,375 at 75% loan to value, a band where rates are usually cheaper and the choice of lenders widest.

A bigger deposit cannot rescue an income that fails the assessment, because the multiple caps the loan whatever you hold in savings. It works the other way instead: deposit strength turns a borderline loan to value into a comfortable one, and comfort is what lenders reward with their best rates.

Gifted money counts the same as saved money inside this arithmetic. A deposit given by a parent or another family member stacks on top of the loan in full, and most lenders accept it with a signed letter confirming the money is a gift rather than a loan. What they will not accept is a deposit that is secretly borrowed, because a repayment on it would belong in the debt deduction and change the whole assessment.

Raising your ceiling before you apply

Time and tidiness move the number more than negotiation does. The levers that work are the ones inside the calculation: income, debts, deposit, and the multiple a lender is willing to apply to a profile like yours.

Clear committed debts first, for the thirty six to one reason the debt section sets out. Then give the application clean statements: three to six months without new credit agreements or overdraft excursions reads as lower risk, and a pay rise that has landed in your salary counts in full where a promised one counts for nothing.

Finally, match the lender to the case. Self employed income, a short contract history, a property with a commercial element or a need for a higher multiple all have lenders who price them routinely and lenders who decline them on sight, and a broker who knows the difference is usually worth more than a tenth of a percent off the rate.

Where the Mortgage Affordability Calculator gets its figures

Rates, bands and thresholds follow published HMRC and gov.uk figures for the 2026/27 tax year, held in one table that every tool reads. April arrives, the table changes, and the results move together.

Earlier years stay available through the year selector, so a late self assessment runs on the numbers that applied at the time rather than today's.

Some cases still need an accountant. K codes carrying negative allowances, bespoke sacrifice arrangements, the annual allowance taper for very high earners, and anything involving two employments at once.

About this calculator

The Mortgage Affordability Calculator estimates how much a UK lender might let you borrow based on your income, deposit and existing monthly commitments.

Frequently asked questions

How much mortgage can I afford on £50,000 salary?+

At the typical 4.5x income multiple, a £50,000 salary supports around £225,000 of borrowing before deposit and debts. Add a £30,000 deposit and you are looking at roughly a £255,000 property. Lenders then stress-test the payment at a higher rate, which can trim the final offer.

What income multiple do UK lenders use?+

Most high-street lenders use around 4.5 times your gross annual income as the headline multiple, with some stretching to 5x or 5.5x for high earners with clean credit. It is a starting point, not a promise: the affordability assessment on your actual spending decides the final figure.

Do debts reduce how much I can borrow?+

Yes. Lenders subtract your committed monthly payments, credit cards, loans, car finance, from what you can afford. Our calculator applies a haircut for monthly debts so the estimate reflects how lenders actually think. Clearing debts before applying is one of the fastest ways to borrow more.

Can I get a joint mortgage with a partner?+

Yes, and lenders usually count both incomes, which can substantially raise the amount you can borrow. Both applicants are jointly liable for the full debt, and both credit files are assessed. Enter both incomes in the calculator to see the joint figure.

How much deposit do I need for a mortgage?+

Most lenders want at least 10% deposit, with the best rates reserved for 25% or more. A bigger deposit lowers your loan-to-value, unlocks cheaper rates and can raise the amount you are offered. Five percent deposits exist but come with higher rates and stricter checks.

Does being self-employed change affordability?+

Lenders typically average your last two to three years of self-employed income, and some use the lower of the years rather than the average. Keep clean accounts and tax returns: gaps or falling income make underwriters cautious even when the headline multiple looks fine.

Why is the lender's offer lower than the calculator says?+

Calculators use the headline income multiple, but lenders also stress-test at a higher interest rate, currently around 8%, and scrutinise childcare, commuting and lifestyle spending. If the offer came back lower, the stress test or your monthly outgoings are usually the reason.