How much could you borrow for a mortgage?
Most borrowing calculators multiply your salary and stop there. This one also checks what your monthly budget can actually carry, how much of your savings is left for a deposit once buying costs are covered, and what the payment would look like if rates rose.
The result is a planning estimate, not a decision in principle. Each lender uses its own criteria, and you’ll need a lender or broker to confirm what you can borrow.
Two limits, and the lower one wins
The calculator works out two separate borrowing limits and uses whichever is smaller.
- Your budget limit: take-home pay minus debt repayments, essential spending and other housing costs. What’s left is the most you could put towards a mortgage each month, which is converted into a loan at your chosen rate and term.
- Your income multiple limit: gross annual income multiplied by the figure you choose, such as 4.5.
For example, take someone earning £60,000 a year, with take-home pay of about £3,780 a month. After £250 of debt repayments, £1,700 of essential spending and £430 of other housing costs, £1,400 is left for the mortgage. At 4.5% over 25 years, that supports about £251,900. The income multiple limit is £270,000 (4.5 × £60,000), so the estimate is £251,900.
Stretch the same budget to 30 years and it supports about £276,300, but the income multiple caps it at £270,000.
An income multiple is a ceiling, not a promise
Many lenders cap borrowing at about four and a half times income, and some go higher for certain professions or higher earners. Raising the multiple in the calculator shows what a more generous lender might allow, but it doesn’t make you eligible. Lenders also look at which income they’ll accept, your credit history, the property and the mortgage term.
How much of your savings goes on the deposit
Your deposit is what’s left of your savings after buying costs and an emergency fund. The emergency fund is your essential monthly spending multiplied by the number of months you choose. MoneyHelper suggests three to six months of essential outgoings.
With £60,000 saved, £8,000 of buying costs and six months of £1,700 spending (£10,200) set aside, £41,800 is left for the deposit. If costs and the reserve add up to more than your savings, the deposit shows as zero rather than a negative figure.
Include stamp duty in your buying costs. The calculator doesn’t work out SDLT, LBTT or LTT for you.
Check the higher-rate payment
The stress result shows what the estimated loan would cost if your rate rose by the amount you choose. In the example above, £251,900 costs £1,400 a month at 4.5% but about £1,861 at 7.5%.
The stress test doesn’t lower the headline estimate, and the target-home check uses your normal rate. So a home can show as affordable even if the higher payment wouldn’t fit your budget. Check that figure yourself. It’s a planning scenario, not a copy of any lender’s own test.
Test a specific home
Enter a price and deposit percentage to check a property against your income, monthly payments and available cash. The check doesn’t apply every lender’s LTV limits or product rules.
Watch for one trap: the headline estimate can still show a healthy loan when your savings don’t cover buying costs and the emergency fund. The target cash shortfall shows that gap. Leave room in your budget for repairs, a drop in income and costs you haven’t entered.
For a second view, try MoneyHelper’s mortgage affordability calculator, from the free, government-backed guidance service.
UK mortgage affordability calculator questions
Why is my estimate lower than 4.5 times my salary?
Your monthly budget is the tighter limit. If debts, bills and living costs leave £1,300 a month for a mortgage, that supports about £233,900 at 4.5% over 25 years, whatever your salary. Clearing a £250-a-month car loan would add about £45,000 to that limit.
Should I include my student loan repayments as a debt?
No, not if they come straight out of your pay. Repayments taken through payroll are already deducted from your take-home figure, so entering them again would count them twice.
Can I include my bonus or overtime?
Only if it’s regular. Lenders treat it very differently: some count all of it, many only part, often half, and some ignore it. For a cautious estimate, leave it out of gross income and see how much the result changes when you add it back.
Buying with a partner: what should I enter?
Enter combined gross income, combined take-home pay and both people’s debts and spending. Lenders look at the household as a whole, so a partner’s credit card or car finance reduces what you can borrow together.
Should childcare go in essential spending?
Yes. Lenders count nursery fees, childminders and after-school care as committed costs, and they can cut borrowing noticeably. Leaving them out will overstate what you can afford.
What stress rate should I choose?
There’s no single right figure, but testing at least three percentage points above your expected rate is a sensible check. Ask yourself whether you could still cover the higher payment when your fixed deal ends without cutting essentials.
Why does it say I can borrow enough but still show a shortfall?
The loan estimate and your cash are worked out separately. You might qualify for the borrowing but not have enough savings to cover the deposit, buying costs and emergency fund together. Check the target cash shortfall before you start viewing homes.
Your home may be repossessed if you do not keep up repayments on your mortgage.