Mortgage affordability calculator

How much can you afford — and what will it really cost?

Borrowing power, regional purchase tax, monthly payments, a rate-rise stress test and the all-in cost in one calculation, followed by plain-English guidance.

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About the purchase
Your income
The mortgage
Advanced settingsValuation, lender assumptions, interest-only and buying fees
Valuation and mortgage type
Affordability assumptions
True-cost extras
Planning range · not a lender decision
£180,000 – £202,500

Estimated from £45,000 income at 4.5× · your £255,000 loan is above typical limits.

Monthly payment£1,292.05
Loan-to-value85.0%good
Rate-rise stress test

If your rate rose to 5.5%, the monthly payment becomes £1,447.86 — comfortable at 38.6% of gross monthly income.

True cost of this purchase
Deposit£45,000
SDLT (stamp duty) · 0.0% effective£0
Product fee£999
Legal / conveyancing£1,200
Upfront cost£47,199
Interest over 30 years£210,137
True total cost£257,336
What this means for you
  • This loan is above typical lending limitsBased on income, most lenders would advance up to about £202,500 (at 4.5× income). You're roughly £52,500 above that — you may need a bigger deposit, a cheaper property, or a lender offering a higher income multiple.
  • Comfortable under a rate riseEven if your rate rose to 5.5%, the payment (~£1,448) stays within a manageable share of income.
  • Healthy 85.0% loan-to-valueA deposit this size puts you in a competitive LTV band, which typically means access to lower interest rates.
  • First-time-buyer relief appliedAs a first-time buyer you pay no SDLT on the first £300,000, and 5% only on the portion above it.

General guidance based on your figures — not financial advice. Lenders vary; confirm with a mortgage adviser before committing.

Method

How this calculation works

Borrowing is estimated as income multiplied by your chosen loan-to-income multiple, reduced for committed monthly spending. Repayments use standard mortgage amortisation. The stress payment applies your chosen rate margin, while purchase tax uses the current regional bands and buyer rules.