Most UK lenders cap your mortgage at 4 to 4.5 times your annual gross income, with a smaller number stretching to 5×. Existing monthly debt payments reduce that capacity. This calculator shows your borrowing range across all three multiples, the monthly repayment at each, and flags when a scenario stretches your income.

How this calculation works

Two rules drive what a UK lender will offer you.

Loan-to-income (LTI) caps the loan as a multiple of your annual gross income. The Bank of England's Financial Policy Committee requires lenders to keep no more than 15% of their new mortgage book at an LTI above 4.5×, which is why most products top out at 4.5×. A small number of lenders offer 5× to higher earners (typically £75k+ individual income or £100k+ joint) or to professionals with predictable income growth such as doctors, dentists, lawyers and accountants.

Debt-to-income (DTI) tests your projected monthly mortgage payment plus existing commitments against your income. The calculator above applies the standard lender rule of thumb: every £100 of monthly debt payments reduces your headline LTI capacity by about £4,000. A £400/month car finance payment will cut a £350,000 mortgage to around £334,000 before any other adjustments.

What lenders look at besides income

The headline figure this calculator produces is a starting point, not an offer. Lenders also weigh:

• Credit file. Missed payments in the last six years, defaults, county court judgments, high credit utilisation and recent credit applications all reduce affordability or product availability.
• Employment status. Permanent PAYE is treated most favourably. Self-employed applicants typically need 2–3 years of accounts; contractors are assessed on day rate × 5 × 46–48 weeks; bonus, commission and overtime are usually averaged across 2 years.
• Source of deposit. Lenders ask where the deposit came from. Savings and equity from a sale are simple; family gifts need a gifted-deposit letter; loans for the deposit are usually not acceptable.
• Term length and age. A 30 or 35-year term increases the loan you can support on a given monthly payment. Lenders typically require the mortgage to end before age 70–75.
• Property type. Ex-local-authority flats, high-rise blocks, properties above commercial premises and short leaseholds all narrow your lender choice.

Affordability killers — things that shrink the offer

These are the most common reasons applicants come in below the figure they expected from a calculator:

• Recent BNPL activity. Klarna, Clearpay and similar now appear on credit files and reduce affordability the same way a credit card does.
• Soft-search overdraft use. Persistent overdraft balances in the three months before application signal living beyond means and can lead to declines even with adequate LTI headroom.
• Probation period. Most lenders prefer you to be out of probation. A handful will lend during probation with a written confirmation of permanent status.
• Recent address changes. Frequent moves in the last 3 years can require additional documentation and may delay an offer.
• Unexplained large credits. Anything over ~£1,000 landing in your account in the 3 months before application usually needs a clear paper trail.

First-time buyer notes

Two things are worth knowing if this is your first home.

• Lifetime ISA (LISA) bonus. If you're 18–39, opening a LISA gives you a 25% government bonus on contributions up to £4,000/year. That's up to £1,000/year of free money toward your deposit, provided the property is under £450,000 and you've held the LISA for 12 months before purchase. Plan this with the deposit savings calculator.
• First-time buyer stamp duty relief. FTBs in England and Northern Ireland pay no SDLT on properties up to £300,000, and a reduced 5% rate on the £300k–£500k slice. Above £500k, full standard rates apply with no relief. Run the numbers on the first-time buyer SDLT calculator.

Salary multiples — what each one gives you

Headline borrowing at each multiple, before any debt adjustment. Use this as a sanity check on the calculator output above.

Annual income	Conservative (4×)	Standard (4.5×)	Stretch (5×)

Frequently asked questions

How much can I borrow for a UK mortgage?

UK lenders typically lend 4 to 4.5 times your annual gross income, with a small number going to 5× for higher earners or strong credit profiles. Existing monthly debt commitments reduce your capacity by roughly £4,000 of borrowing per £100 of monthly payments.

What income multiple do most lenders use?

The headline multiple for most UK lenders is 4.5× household income. Some products will offer 4× as a default for borrowers with thinner credit files, and a limited number of lenders will stretch to 5× for higher earners (typically £75k+) or professionals with predictable income growth.

Do monthly debts really affect what I can borrow?

Yes. Lenders run a debt-to-income test alongside the loan-to-income multiple. Every £100 of monthly debt payments (loans, credit cards, car finance, BNPL) typically reduces your maximum mortgage by around £4,000 because that £100 has to come from the same income that would otherwise support mortgage payments.

Does student loan count as a monthly commitment?

Yes — most lenders deduct your student loan repayment from net income when assessing affordability. It's not treated as harshly as consumer debt, but a £200/month student loan repayment can shave £6,000–£10,000 off your maximum mortgage depending on the lender's model.

What deposit do I need?

5% is the absolute minimum for most UK residential mortgages. 10% opens up materially more products and better rates. 15% is the sweet spot for first-time buyers seeking decent rates without saving for years. 25%+ unlocks the best rates available.

What is the FCA stress test?

Since 2014, FCA rules have required lenders to check that borrowers could still afford their mortgage if interest rates rose. The original 3% bolt-on stress test was withdrawn in August 2022, but lenders still run their own internal stress tests, typically at the standard variable rate plus 1%, before issuing an offer. Use the mortgage stress test calculator to see what your payments would look like if rates rose.

Can two incomes be added together for a joint mortgage?

Yes. For a joint mortgage, lenders apply the income multiple to combined household income. Two applicants on £40,000 each can typically borrow around £360,000 at the standard 4.5× multiple — the same as one applicant on £80,000, before commitments are deducted.

How accurate is this calculator?

It gives a reliable estimate using the standard loan-to-income rule that drives most lender decisions. It does not account for credit score, time in employment, type of income (bonus, commission, self-employment), recent missed payments, or lender-specific quirks. Treat the result as the headline figure — your actual offer will sit somewhere within ±15% of it for most applicants.

Once you know your price ceiling

Want to understand your take-home pay before working out your budget? PayslipCheck breaks down a UK payslip line by line. To plan your deposit timeline including the LISA bonus, our sister site PennyWise Finance has a first-time buyer savings guide.

Calculation rules last reviewed: 24 May 2026.