UK mortgage payments and stamp duty
Buying a home in England or Northern Ireland involves two major upfront costs: your mortgage deposit and Stamp Duty Land Tax (SDLT). This calculator estimates your monthly repayment, total interest, and SDLT based on current residential rate bands.
For a detailed SDLT breakdown with first-time buyer relief and surcharges, use the Stamp Duty Land Tax UK calculator or the stamp duty calculator. To estimate take-home pay for affordability planning, try the UK take-home pay calculator.
Monthly repayment formula
Where P is the loan amount (home price minus deposit), r is the monthly interest rate, and n is the number of monthly payments.
Stamp duty bands
Residential SDLT rates effective from 1 April 2025 apply progressively:
- 0% on the portion up to £250,000
- 5% on £250,001 to £925,000
- 10% on £925,001 to £1,500,000
- 12% above £1,500,000
Worked example
A £500,000 home with a £125,000 deposit leaves a £375,000 loan at 5% over 25 years. The monthly repayment is about £2,192. Stamp duty on the purchase price is £12,500 (5% on the £250,000 above the nil-rate band).
Frequently asked questions
What is Stamp Duty Land Tax?
Do first-time buyers pay less SDLT?
How is the UK mortgage payment calculated?
What rate bands does this calculator use?
Are my inputs stored on a server?
Resources and references
The formulas and methods in this calculator were checked against these independent sources.