How Much Mortgage Can You Actually Afford in the UK?

Mortgage calculators love to give you a big, encouraging number. But the figure a lender will actually approve, and the figure you can comfortably live with, are often two very different things. In the UK, how much you can borrow is shaped by income multiples, your deposit, an affordability assessment of your real spending, and a stress test that imagines rates rising. This guide from the SafeToSpend team walks through each piece so you can judge what is genuinely sensible rather than simply possible.

The income multiple: the famous 4.5x cap

Most UK lenders work to a loan-to-income (LTI) limit of around 4.5 times your gross annual income. So a household earning £50,000 might be offered a maximum of roughly £225,000. Regulators allow banks to lend above 4.5x on a limited share of their lending, so some borrowers, often higher earners or certain professionals, may stretch to 5x or beyond. Many lenders sit closer to 4x for applicants with thinner affordability or higher outgoings.

Joint applications usually combine both incomes, though lenders weigh the total against your combined commitments rather than simply adding two big numbers together.

Household income	At 4x	At 4.5x	At 5x
£30,000	£120,000	£135,000	£150,000
£50,000	£200,000	£225,000	£250,000
£75,000	£300,000	£337,500	£375,000

These are illustrative ceilings, not guarantees. The actual offer depends on the affordability check below.

What actually counts as income

Lenders rarely take 100% of everything you earn. Basic salary is counted in full, but variable pay is treated more cautiously.

• Basic salary: counted fully.
• Bonus, overtime, commission: often counted at around 50%, or averaged over two or three years.
• Self-employed profit: typically an average of the last two years' figures, evidenced by accounts or tax calculations.
• Benefits and pensions: some, such as Child Benefit or certain pension income, may be accepted, but policies vary widely.

Deposit, LTV and how it changes your rate

Loan-to-value (LTV) is the size of your loan against the property price. A £40,000 deposit on a £200,000 home is a 20% deposit, or 80% LTV. The lower your LTV, the lower the lender's risk, and the better the interest rate you are usually offered. Rates step down at key thresholds, commonly 95%, 90%, 85%, 80%, 75% and 60% LTV.

Deposit	LTV	Typical rate tier
5%	95%	Highest rates, fewer deals
10%	90%	Improving choice
15-25%	85-75%	Mainstream competitive rates
40%+	60%	Best advertised rates

Pushing from a 90% LTV to 85% LTV (raising your deposit from 10% to 15%) can shave a meaningful amount off your monthly payment, so saving a little longer sometimes beats buying immediately.

The stress test

Even if the headline rate looks affordable, lenders must check you could still cope if rates rose. They assess your payments against a higher notional rate, and they subtract your committed outgoings, credit cards, loans, car finance, childcare and other regular costs, before deciding what is left for a mortgage. This is why two households on identical salaries can be offered very different amounts: the one with a car loan and high childcare costs has less headroom.

The maximum you can borrow is a ceiling set by the lender's risk appetite, not a recommendation tailored to your life.

Why the most you CAN borrow isn't the most you SHOULD

Borrowing to your limit leaves no cushion for rate rises at remortgage, a job change, a new baby, or simply wanting to save and enjoy life. Many people find a payment that swallows much more than around 35% of take-home pay starts to feel tight. Build in room for council tax, energy, insurance, maintenance and emergencies, none of which appear on a mortgage calculator. A slightly smaller loan with breathing space is usually the calmer, more resilient choice.

FAQ

Does a bigger deposit reduce how much income I need?

Indirectly, yes. A larger deposit means a smaller loan, so your required income multiple falls and you unlock lower rates, which makes the monthly cost easier to pass on affordability.

Do student loans affect what I can borrow?

They can. Student loan repayments reduce your take-home pay, and lenders factor that lower net income into affordability, though they usually treat it differently from consumer debt.

Can I borrow more than 4.5x my income?

Sometimes. A minority of lending can exceed that multiple, and some lenders offer higher multiples to certain higher earners or professionals, but it is not the norm.

Will clearing debts before applying help?

Often, yes. Reducing monthly commitments frees up affordability headroom, which can increase the amount a lender is willing to offer.

Treat any borrowing figure as a starting point, not a target. Work out the monthly payment that leaves you comfortable, stress test it yourself against a higher rate, and let that, rather than the lender's ceiling, guide what you offer on a home. A mortgage you can afford on a good month is fine; one you can afford on a difficult month is far better.

This guide is general information from the SafeToSpend editorial team (NexoraOS) and is not financial advice. Figures and rules change — check the current position before acting.