Take a single buyer on £50,000 with a £50,000 deposit. At the mainstream 4.5 times income multiple, the maximum loan is £225,000. Add the deposit and the most they can offer on a property is about £275,000. That puts the loan-to-value at roughly 82 percent, comfortably inside standard lending territory where rates are competitive. A couple earning £50,000 between them would borrow the same £225,000, since the multiple applies to combined income. Push the multiple to 5.5, which some specialist lenders allow for higher earners, and the same buyer could borrow £275,000, lifting the budget to £325,000, though affordability stress tests on monthly outgoings still apply.
How it is calculated
The estimate multiplies your total household income by an income multiple to get the maximum loan, then adds your deposit to find the highest property price you could offer. Most mainstream UK lenders cap borrowing at 4.5 times income, a direct result of the Financial Conduct Authority limiting the share of high loan-to-income mortgages, above 4.5 times, that a lender can write. A handful of specialist lenders stretch to 5 or 5.5 times for high earners or certain professions, which is why the multiple is adjustable here. The loan-to-value is the loan divided by the property price, and a lower figure unlocks better rates because the lender takes less risk. This is a borrowing-capacity estimate, not a formal decision in principle. Real underwriting also stress tests your monthly commitments, credit history, and spending, so your actual offer may be lower.
Frequently asked questions
Why 4.5x?
FCA caps the percentage of high-loan-to-income mortgages (above 4.5x) at 15% of a lender's new lending volume. Most mainstream lenders cap at 4.5x as a result. A few specialist lenders offer up to 5.5x for high earners or specific professions.
Does deposit size affect how much I can borrow?
Your deposit does not change the income multiple calculation, so it does not directly increase your maximum loan. It does raise the maximum property price you can offer and lowers your loan-to-value ratio, which can unlock better interest rates and wider lender choice.
Does the calculator account for existing debts or outgoings?
No. This tool estimates the theoretical maximum based on the income multiple alone. Lenders also run affordability stress tests that factor in credit card balances, car finance, student loans, and essential living costs, so your actual approved loan is likely lower than this figure.
Can I borrow more as a joint applicant?
Yes. Lenders apply the income multiple to combined household income, so adding a second borrower with any positive income raises the maximum loan proportionally. Enter both incomes in the calculator to see the combined borrowing capacity.