Mortgage calculator

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

Most calculators answer one question. This one shows what you can borrow, your stamp duty across England, Scotland and Wales, your monthly payment, what happens if rates rise, and the true all-in cost — then explains what it means for you.

About the purchase
Your income
The mortgage
True-cost extras (optional)
You could borrow
£180,000 – £202,500

Based on £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.

How this calculator works

Borrowing is estimated as income × your chosen multiple (4.5× is the common default), reduced for committed monthly spending. The stress test follows the FCA's approach of checking affordability at a higher rate. Stamp duty uses the current 2026/27 bands for your region. Every rate and its official source is listed on the How we calculate page.