Mortgage Calculator UK
Calculate monthly mortgage repayments in GBP (£) and Stamp Duty Land Tax (SDLT) liability under HMRC residential rates for England & Northern Ireland.
Calculator Inputs
Total agreed purchase price of the UK residential property.
Cash deposit contributed towards the property purchase.
Annual mortgage interest rate.
Repayment duration (standard is 25 years).
Additional months (0-11). For 18 months, enter 1 year 6 months.
- Monthly Repayment
- $1,556.33
- Stamp Duty (SDLT)
- $7,500.00
- Effective Stamp Duty Rate
- 2.14%
- Total Borrowing (Mortgage)
- $280,000.00
- Deposit Percentage
- 20%
- Total Interest Payable
- $186,899.00
- Total Mortgage Cost
- $466,899.00
About these results
CalcSpectrum calculators produce automated estimates using established formulas and the specific values you enter. Because real-world outcomes depend on input accuracy, mathematical assumptions, and rounding conventions, please verify critical figures with an appropriately qualified financial, tax, medical, legal, or other professional, as relevant.
Financial Notice: These figures are informational estimates for personal planning only. They do not constitute financial, investment, tax, or legal advice, nor do they represent a lending offer or credit approval. Provider and financial institution figures, rates, fees, and underwriting requirements may differ.
How It's Calculated
Formula
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.