Mortgage Calculator UK
Calculate monthly mortgage repayments in GBP (£) and Stamp Duty Land Tax (SDLT) liability under HMRC residential rates for England & Northern Ireland.
How It's Calculated
Formula
\text{Monthly Payment} = P \cdot \frac{r(1+r)^n}{(1+r)^n - 1}This UK mortgage calculator estimates monthly capital and interest repayment amounts alongside official HMRC Stamp Duty Land Tax (SDLT) obligations for properties in England and Northern Ireland. Monthly repayments are calculated using standard compound amortization based on loan principal, annual interest rate, and term in years.
Worked Examples
Standard Home Purchase: £300,000 price, £60,000 deposit (20%), 4.5% rate, 25-year term
- Deposit is 20% (£60,000), resulting in borrowing of £240,000.
- Monthly interest rate = 4.5% / 12 = 0.375% per month; 300 total payments.
- Monthly repayment (principal and interest) = £1,333.95.
- Total mortgage interest payable = £160,185.00; total mortgage cost = £400,185.00.
- HMRC Stamp Duty (post-1 April 2025): 0% on first £125k (£0) + 2% on £125k–£250k (£2,500) + 5% on £250k–£300k (£2,500) = £5,000 SDLT.
Frequently Asked Questions
Which parts of the UK does the Stamp Duty calculation cover?
Stamp Duty Land Tax (SDLT) applies strictly to property purchases in England and Northern Ireland. Property transactions in Scotland are subject to Land and Buildings Transaction Tax (LBTT), and purchases in Wales are subject to Land Transaction Tax (LTT).
What are the current standard residential SDLT rates?
Under standard HMRC rules (effective from 1 April 2025): 0% on the first £125,000, 2% on £125,001 to £250,000, 5% on £250,001 to £925,000, 10% on £925,001 to £1,500,000, and 12% on the portion above £1,500,000.
Is mortgage interest relief available for home buyers?
Residential owner-occupiers in the UK cannot deduct mortgage interest against their personal income tax liability.