How much can I borrow for a mortgage in the UK?

Most UK lenders cap mortgages at around 4.5 times your annual income (incomes combined for joint applications). So a £40,000 income suggests a maximum loan near £180,000, though the exact figure depends on affordability checks, outgoings, and credit.

What is loan-to-value (LTV)?

LTV is the loan as a percentage of the property price. A £200,000 loan on a £250,000 home is 80% LTV, meaning a 20% deposit. Lower LTV usually unlocks better interest rates because the lender's risk is smaller.

How is the monthly mortgage repayment calculated?

It uses standard amortization: M = P·r·(1+r)^n / ((1+r)^n − 1), where P is the loan, r is the monthly interest rate, and n is the number of months. A larger loan, higher rate, or shorter term raises the monthly payment.

Does the 4.5x cap include my deposit?

No. The 4.5x multiple applies to the loan only. Your maximum property price is the maximum loan plus your deposit, so a larger deposit lets you buy a more expensive home without borrowing more.

UK Mortgage Affordability Calculator

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UK lenders typically limit a mortgage to about 4.5 times your income. This calculator estimates your maximum borrowing, the loan-to-value of a target purchase, and the monthly repayment at your chosen rate and term.

How it works

Your maximum loan is estimated as 4.5 times total income (incomes summed for joint applicants). The most you can buy is that loan plus your deposit. The monthly repayment on the loan you actually need uses standard amortization:

maxLoan = income × 4.5
M = P·r·(1+r)^n / ((1+r)^n − 1)   (r = monthly rate, n = months)
LTV = loan / property price

If your loan need exceeds the 4.5x cap, the tool flags the shortfall so you can adjust the price or deposit.

Example

With a £40,000 income and a £40,000 deposit, the maximum loan is about £180,000, so the maximum property is roughly £220,000. Buying at £250,000 would need a £210,000 loan — over the cap by £30,000. At £220,000 the £180,000 loan at 4.5% over 25 years costs about £1,000 a month at roughly 82% LTV.

Notes

Estimate only, not a mortgage offer. The 4.5x multiple is a common rule of thumb; real lender limits depend on detailed affordability, stress tests, credit history, existing debts, and the product. Monthly repayment assumes a repayment (not interest-only) mortgage. Verify with a lender or a regulated mortgage broker.