Rowena has rented the same two-bedroom flat in Sheffield for four years. Her rent is £950 a month; she has £20,000 saved, and she earns £38,000 a year. Every time she types “how much mortgage can I get” into a search engine, she gets a different answer — one calculator says £171,000, another says £150,000. None of them explains why the answers differ, or which one a real lender would actually offer her.

This guide gives you the maths behind those answers: the two caps that limit every mortgage, how lenders test affordability, what your deposit does and does not change, and how your rent compares with a mortgage payment.

Quick Answer: Most UK lenders cap borrowing at around 4 to 4.5 times your gross annual household income, and MoneyHelper notes that most people are offered less than that maximum. Your deposit does not raise the income cap, but it decides the price you can buy: price = mortgage + deposit. Every lender also runs its own affordability check on your real outgoings, so debts and childcare can pull your offer below the headline multiple. Get an Agreement in Principle for a figure you can rely on — online calculators are estimates only.

This guide reflects the position in October 2026 and is general information, not mortgage advice. Lending criteria differ between lenders, so speak to an FCA-regulated mortgage adviser before making an offer. Figures marked “illustrative” use example rates chosen to show the arithmetic; they are not average market rates.

The Two Caps That Decide Your Maximum

Every mortgage offer is squeezed by two caps at once, and you are offered the lower of the two. The first is the income multiple: a ceiling expressed as a multiple of your gross annual income. The second is the affordability check: a look at your income after committed outgoings and living costs, testing whether the monthly payment leaves you enough to live on. A renter with no debts will usually hit the income cap; a renter with car finance and childcare costs will often hit the affordability cap well before the multiple.

There is a third limit renters feel most sharply: your deposit. The Bank of England has found that for around 75% of renters, the deposit — not income — caps the home they can buy, because the loan-to-value limit turns your deposit into a maximum loan: with a 5% deposit you can only borrow 95% of the price. Income decides the ceiling; the deposit decides whether you can reach it. Our deposit-saving guide covers the saving side — this guide covers the borrowing maths.

Income Multiples: What 4.5 Times Really Means

The headline rule is simple. Take your gross annual income — before tax, including anyone buying with you — and multiply it. Most high-street lenders use 4 to 4.5 times income as their standard ceiling. MoneyHelper puts it plainly: the most you can borrow is usually capped at four and a half times your annual income, but this is not guaranteed, and most people are offered less.

Some lenders stretch further for particular borrowers — higher earners, people with strong credit records and low loan-to-value ratios — and some first-time-buyer schemes have offered 5 to 5.5 times income, with a few advertising up to 6 times in 2026. Treat those as exceptions: they carry stricter conditions and still have to pass the affordability check.

Gross annual household income	At 4 times income	At 4.5 times income
£25,000	£100,000	£112,500
£30,000	£120,000	£135,000
£38,000	£152,000	£171,000
£50,000	£200,000	£225,000
£62,000	£248,000	£279,000
£80,000	£320,000	£360,000

Joint applications use combined income, which is why buying with a partner usually lifts the ceiling most: two incomes of £31,000 each give a £279,000 ceiling at 4.5 times. But joint borrowing means joint liability: if one income stops, the other borrower is still responsible for the whole payment.

The Affordability Check Lenders Actually Run

The income multiple is the ceiling; the affordability check is the inspection underneath it. Under the Financial Conduct Authority’s responsible-lending rules, a lender must assess whether you can afford the mortgage from your verified income, your committed monthly payments, and an allowance for ordinary living costs.

Committed payments are deducted first: credit card minimums, personal loans, car finance, student loan repayments and child maintenance. Then comes everyday spending — food, travel, energy bills, council tax and childcare — sometimes taken from your bank statements, sometimes estimated from standard figures. What is left, with a safety margin, is the amount available for a mortgage payment.

Rent itself is not usually treated as a committed outgoing, because the mortgage replaces it — but a lender will still look at your bank statements, and missed rent or regular overdraft use will count against you. A clean record of paying £950 a month in rent on time is evidence you can sustain a similar mortgage payment. If your outgoings are high, the affordability check — not the multiple — sets your limit.

Stress Tests: What Changed in 2022 and 2026

Many older guides still describe a single official “stress test” of 3% above your mortgage rate. That description is out of date. In 2014 the Bank of England’s Financial Policy Committee recommended a loan-to-income flow limit and an affordability test checking borrowers could pay if rates rose 3 percentage points above their lender’s reversion rate. In June 2022, the Committee withdrew the affordability test recommendation with effect from 1 August 2022, judging that the loan-to-income limit plus the FCA’s affordability rules gave enough protection. Most lenders kept running their own stress tests, but each lender now sets its own stressed rate.

The loan-to-income limit also changed recently. From 2014, each lender was individually limited so that no more than 15% of its new mortgages could be at 4.5 times income or above. On 14 October 2026, the Prudential Regulation Authority and the FCA finalised new rules, effective from 28 October 2026, replacing the firm-level cap with a market-wide aggregate limit of 15%. Individual lenders may now exceed 15% of their own lending at high ratios, provided the market total stays consistent with 15%. The change gives lenders more flexibility; it does not require any lender to lend more.

In practice, expect your lender to test your payment above the rate you will actually pay — perhaps 1 to 3 points higher. Run that test on yourself: if the higher payment would break your budget, borrow less.

Your Deposit, LTV and the Price You Can Reach

Your deposit and your mortgage are two halves of the same price. Loan-to-value, or LTV, is the mortgage as a percentage of the price: a £180,000 mortgage on a £200,000 home is 90% LTV, with your £20,000 deposit the other 10%. MoneyHelper notes that most mortgages ask for a deposit of at least 5% to 10% of the price, and a larger deposit generally means a lower LTV, a wider choice of products, and lower payments.

The two caps can point in different directions. A high salary with a small deposit can leave you income-rich but deposit-poor: approved to borrow £225,000, but with only a £10,000 deposit you can only buy at 95% LTV, so your maximum price is £10,000 ÷ 5% = £200,000. A large deposit with a modest salary gives the opposite problem: the income multiple caps the loan below £200,000, whatever the deposit.

Deposit	LTV on a £200,000 home	Loan needed	Effect
5% (£10,000)	95%	£190,000	Smallest choice of products; higher payments
10% (£20,000)	90%	£180,000	Standard first-time-buyer territory
15% (£30,000)	85%	£170,000	Wider product choice
20% (£40,000)	80%	£160,000	Lower payments; often better rates

Remember the cash beyond the deposit: survey and legal fees, moving costs, and a buffer for the first months — advisers commonly suggest around three months of expenses in reserve after you move.

Rent Versus Mortgage: The Monthly Comparison

Renters naturally compare the mortgage payment with the rent they pay now, but it is not the whole picture. A capital-and-interest payment depends on the loan, the rate, and the term. At an illustrative rate of 4.5% over 25 years, a £180,000 loan costs about £1,000.50 a month, while a £225,000 loan costs about £1,250.62. Stretch the £225,000 loan to 30 years, and the payment falls to about £1,140.04 — but you pay interest for five more years, so the total cost rises even as the monthly figure falls.

Then there are the costs rent does not include. As an owner you pay for buildings insurance, maintenance, and repairs — if the roof leaks, the bill is yours. You also gain something rent never gives: every capital-and-interest payment reduces what you owe, building your own equity. Interest-only mortgages look cheaper but do not reduce the balance.

Monthly comparison	Renting now	Owning (illustrative)
Core monthly payment	£950 rent	£1,000.50 mortgage on £180,000 at 4.5% over 25 years
Repairs and maintenance	Landlord’s responsibility	Yours — budget monthly even in good years
Buildings insurance	Landlord’s cost	Yours, and usually a mortgage condition
Equity built each month	None	Part of each payment reduces your loan balance
Flexibility to move	Notice period under your tenancy	Selling takes months and costs fees

If your mortgage payment would be close to your rent, that is encouraging — but check the stressed payment too. At an illustrative 6.5% the same £180,000 loan over 25 years costs about £1,215.37 a month, and at 7.5% about £1,330.18. If you could not pay the higher figure for long, a smaller loan or a longer term is safer.

What Lenders Count as Income

Not all income counts equally. Lenders verify income from documents, not from what you tell them. Salaried employees have the simplest path: recent payslips and bank statements, sometimes a P60. Overtime, commission and bonuses usually count only if regular and evidenced over time. Second jobs and freelance income can count with a track record; pension income, investment income and child maintenance can count where stable and documented. For joint applications, both incomes count, but both credit records are assessed too.

Self-employed renters face the strictest test. MoneyHelper notes that self-employed applicants are typically asked for two or three years of tax returns and business accounts, and lenders generally use taxable profit — not turnover — so deductions that lower your tax bill also lower the income a lender will use. Some lenders use the latest year if profits have risen; others average two or three. If you are self-employed, keep your accounts clean, file on time, and talk to a broker early.

What Shrinks the Amount You Can Borrow

If the multiple gives you the ceiling and the deposit gives you the price, your outgoings decide where you actually land. Car finance is often the largest drag: £250 a month is £3,000 a year already committed. Credit card minimums add up across cards, and student loan repayments, childcare and maintenance all count as committed outgoings. Even “buy now, pay later” balances can appear on a credit file, so tidy them before applying.

Your credit record matters alongside your outgoings. Missed payments, defaults and county court judgments can close off whole lenders, leaving only specialist products at higher rates. Check your credit report before you apply, correct errors, and avoid new credit applications beforehand.

Outgoing	Effect on borrowing
Car finance	Monthly payment deducted from affordable amount
Credit card minimums	Each balance adds a commitment
Student loan	Counted as a committed outgoing
Childcare costs	Reduces what is left for a mortgage

Two Worked Examples

The examples below use fictional renters and illustrative rates.

Worked example — Rowena, Sheffield. Rowena earns £38,000, pays £950 a month in rent, and has saved a £20,000 deposit. Her income ceiling at 4.5 times is £38,000 × 4.5 = £171,000, giving a maximum price of £171,000 + £20,000 = £191,000 — so a £200,000 home is out of reach unless she saves a further £9,000. At an illustrative 4.5% over 25 years, a £171,000 loan costs about £950.48 a month (£1,000.50 × 171 ÷ 180), almost exactly her current rent. At an illustrative 6.5% it costs about £1,154.60 a month (£1,215.37 × 171 ÷ 180) — the figure she should budget against.

Worked example — Crispin and his partner, Bristol. Crispin earns £34,000 and his partner earns £28,000, giving a joint income of £62,000 and a 4.5-times ceiling of £62,000 × 4.5 = £279,000. With a £30,000 deposit, their maximum price on income alone is £279,000 + £30,000 = £309,000. But Crispin has £220 a month in car finance, and their lender’s affordability check offers less than the ceiling. They settle on a £250,000 loan and a £280,000 home. At an illustrative 4.5% over 25 years the payment is about £1,389.58 a month (£1,000.50 × 250 ÷ 180), against rent of £1,150 — £239.58 more than they pay now. At an illustrative 6.5% it rises to about £1,688.02 a month (£1,215.37 × 250 ÷ 180), so they delay their purchase to clear the car finance first.

Both examples make the same point: the multiple tells you the ceiling, the deposit tells you the price, and the affordability check — plus your own honest stress test — tells you what you should actually borrow.

How to Increase What You Can Borrow

If the numbers come out lower than you hoped, start with the cheapest lever: clear or reduce committed monthly payments, especially car finance and credit card balances, and let your bank statements show a few clean months. Next, check your credit report and fix errors.

Then look at the structure. A larger deposit lowers the LTV and can unlock better products, which is why the savings plan in our deposit guide matters. A longer term lowers the monthly payment and can raise the affordable loan, though it increases total interest. Buying jointly lifts the income ceiling most. Some lenders offer higher multiples or first-time-buyer schemes, including shared ownership, which our shared ownership guide explains. Finally, get the evidence in order — payslips, bank statements, tax returns if self-employed — then seek an Agreement in Principle, which usually lasts 60 to 90 days. If you are still renting while you search, our guides to negotiating your rent and challenging a rent increase can keep costs down.

FAQs

Final Thoughts

The question “how much mortgage can I get” has three answers: the income multiple gives you the ceiling, the affordability check gives you the realistic offer, and your deposit gives you the price. For most renters, the deposit is the binding constraint, which is why the saving plan and the borrowing maths belong together.

Start with the ceiling, then do the honest work: add up your committed outgoings, test the payment at a higher rate, and compare the stressed figure with your rent. If the numbers work, get an Agreement in Principle and house-hunt at a plausible price. If they do not work yet, reduce monthly commitments, build the deposit, tidy your credit record, and consider a longer term or shared ownership. Buying later at a payment you can sustain beats buying now at one you cannot.

Read our deposit-saving guide alongside this one. If you are staying renting for another year, our rent increase guide can help you keep that year affordable.

Further Reading

• MoneyHelper – What mortgage can I afford?
• Bank of England – High loan to income lending
• Bank of England – When applying for a mortgage, are renters more constrained by their savings or their income?