Mortgage Affordability Calculator (UK)
How much house can you borrow for? Enter income, deposit, interest rate and term and see the maximum loan, the monthly repayment and the total interest bill.
Income and deposit
Loan terms
Max property budget: £0
Monthly repayment: £0
A guide, not a mortgage offer. Actual lending depends on credit history, regular outgoings, contract type and stress-tested affordability — a broker can sharpen this estimate.
Income multiples are a rule of thumb
Most UK lenders apply an income multiple cap — the loan can't exceed roughly 4.5× your combined gross income. But the real test is affordability: your monthly commitments against a stress-tested payment. That's why a couple on £60,000 joint income with a £500 monthly car loan often gets offered less than a couple on £60,000 with no outgoings.
This calculator uses the multiple as a fast filter, and shows you the stressed monthly payment as a percentage of income so you can sanity-check affordability too.
Don't forget the other buying costs
The budget shown above is the property price you can reach — not the total cash outlay. On top you'll need:
- Stamp duty — £0 to £20,000+ depending on nation, price and buyer type. See our free UK stamp duty calculator.
- Conveyancing and searches — £1,500–£3,000 typical
- Survey — £300 (basic) to £1,200+ (building survey)
- Moving — £500–£2,000 depending on distance and volume
Build these into your deposit plan so you don't arrive at completion short.
Where Offrly fits
Knowing what you can borrow is half the equation. Knowing what the property is actually worth is the other. Offrly's AI reads each comparable's photos (garden, condition, layout, finish) the way a seasoned property analyst would, and a hyperlocal regression resolves prices to the street rather than the postcode — returned in about 30 seconds. A sharp free first-pass price. When an agent says "£425,000", you'll know whether that's a price or a pitch.
Disclaimer: This calculator is for illustration only. It is not a mortgage offer and not financial advice. Actual lending depends on your full financial profile, credit history, regular outgoings and the lender's stress-tested affordability model. For a formal decision in principle, speak to a whole-of-market mortgage broker or a lender directly. Offrly valuations are indicative market guidance, not regulated valuations — use a RICS-qualified surveyor for mortgage, insurance or probate purposes.
Knowing what you can borrow is half the answer
The other half: is the asking price fair? Offrly's AI reads each comparable's photos, and a hyperlocal regression resolves prices to the street rather than the postcode — a sharper free first-pass price than anything else online, in about 30 seconds.
Value a property free →FAQ: Mortgage Affordability Calculator (UK)
Is this the same as a Mortgage in Principle?
No. A Mortgage in Principle (MIP) is a soft credit check with a specific lender against their affordability model. This calculator uses the UK mainstream rule-of-thumb multiple — useful for budgeting, but a MIP is what estate agents actually want to see.
What affordability multiple do UK lenders use?
Typical cap is 4.5× combined income. A few lenders will go to 5× or, with strong professional income, 5.5×. Expensive areas sometimes see higher multiples; lenders stress-test monthly payments against rate rises.
Why does term matter so much?
A 30-year term has a lower monthly payment than a 25-year term — but you pay much more interest over the life of the loan. Going 5 years longer on a £250k loan at 4.5% can add £30,000+ to total interest.
What's the 40% stress-test rule?
UK lenders generally won't let mortgage payments take more than around 40% of gross monthly income, and stress-test against a rate shock of roughly 1–3 percentage points. If your payment ratio exceeds 40%, this calculator flags it.
Does deposit size affect the rate I get?
Yes. Lenders price by loan-to-value (LTV) band — a 75% LTV rate is typically meaningfully cheaper than a 90% LTV rate. Putting more down can unlock a lower rate, which can sometimes let you borrow more under affordability rules.