Mortgage Affordability Calculator
What's My Mortgage Affordability?
Calculate how much you can really target once property value, offers over, and purchase tax all compete for the same cash.
Mortgage Details
Buyer type
Affects your purchase tax calculation.
Enter your income, buyer type, and location to see a quick affordability estimate.
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Calculate Monthly PaymentsUnderstanding Mortgage Affordability
How lenders decide what you can borrow
How mortgage affordability works
Lenders balance three things at once: your income ceiling, your available deposit, and the total cash the purchase demands. The binding limit is whichever constraint bites first.
Income sets the ceiling
Most lenders cap borrowing at 4–4.5× your gross annual income. Joint applications combine both salaries.
Deposit sets the floor
A 5% minimum deposit unlocks most deals; 10–25%+ earns progressively better interest rates as your LTV falls.
Purchase costs eat into cash
Stamp duty, offers over the Home Report value, legal fees and surveys all draw from the same cash as your deposit.
How lenders count your income
- Joint applications — both salaries combined, so a £35k + £30k couple can borrow up to £292,500 at 4.5×.
- Bonuses & overtime — some lenders include a portion, but rarely the full amount.
- Self-employed — expect to provide 2–3 years of accounts or tax returns to evidence earnings.
How deposit size changes rates
Property taxes by region
England & N. Ireland use SDLT. Scotland levies LBTT, which includes an "Offers Over" convention above the Home Report value. Wales uses LTT. Each has different thresholds and first-time buyer reliefs. Select your region in the calculator above.
Understanding Loan-to-Value (LTV)
LTV is your mortgage as a percentage of the property's value. A £200k home with a £20k deposit = 90% LTV. Every 5% you can reduce LTV by saving more or targeting a lower price typically drops you into a cheaper rate band, saving thousands over the mortgage term.
What can reduce your limit
- Existing debts (car loans, student loans, credit cards) shrink the income multiple
- A poor credit score may reduce borrowing or require a larger deposit
- High monthly outgoings (childcare, transport, subscriptions) affect affordability assessments
- Non-standard property types (ex-council flats, high-rise) may limit lender choice
Your credit score
Think of your credit score as a report card for your money habits. Lenders use it to judge how risky it is to lend to you.
- A strong score can mean lower rates and a higher borrowing limit
- A weaker score may still qualify, but with less favourable terms
- Check and tidy your report 3–6 months before applying to avoid surprises
Tips to improve your affordability
- Clear high-interest debts before applying to improve your income multiple
- Use a Lifetime ISA to earn a 25% government bonus on savings (up to £1,000/yr)
- Check (and fix) your credit report 3–6 months before applying
- Extending your mortgage term lowers monthly payments; revisit when income grows
Not all properties are equal
The type of home you're buying can affect which lenders will consider you.
- Standard homes — houses and low-rise flats are straightforward for most lenders
- Non-standard — high-rise flats, ex-council, thatched, or studio properties can restrict your lender options or require a larger deposit
- Check with a lender or broker early to avoid surprises on unusual property types
Educational guidance only — not financial or mortgage advice. All figures are estimates based on typical lending multiples. Actual mortgage offers depend on your full credit profile, individual affordability assessment, and lender criteria. Speak to a qualified mortgage adviser before making any decision.
See how lenders judge affordability
The mortgage affordability guide covers deposit size, loan-to-value, stress testing and the main checks behind borrowing limits.