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Free UK Mortgage Calculator

Estimate your UK mortgage payment and Stamp Duty Land Tax (SDLT) from the property price, deposit, rate, and term.

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Key Features

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Get accurate results in real time with our optimized algorithm.

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Buying a home in the UK involves not just the mortgage payment, but also Stamp Duty Land Tax (SDLT) — a tiered tax on the purchase price that most other countries' mortgage calculators don't need to account for.

This calculator estimates your monthly mortgage payment using the standard repayment formula, and separately estimates SDLT using the standard residential rate bands for a single main home.

How it works

Enter the property price, your deposit, the annual interest rate, and the mortgage term in years. The tool subtracts the deposit to find the mortgage amount, applies the standard payment formula, and separately estimates SDLT by applying each tax band's rate to the portion of the price that falls within it.

  1. Enter property price (£).
  2. Enter deposit (£).
  3. Enter annual interest rate (%).
  4. Enter mortgage term (years).
  5. Click Calculate to see your results.

Examples

A £350,000 home with a 10% deposit

A £350,000 property with a £35,000 deposit, financed at 5.25% over 25 years, comes to about £1,888/month, with an estimated £7,500 in Stamp Duty Land Tax.

Who should use it

  • Budgeting for a home purchase in England or Northern Ireland.
  • Comparing how different deposit amounts affect both the mortgage payment and the loan-to-value ratio.

Industry applications

  • UK residential mortgage lending
  • Personal home-buying budgeting

Advantages

  • Combines the mortgage payment calculation with a genuinely UK-specific tax estimate in one place.
  • Uses the real tiered SDLT band structure, not a flat percentage.

Limitations

  • Doesn't account for first-time-buyer relief or the additional-property surcharge.
  • SDLT thresholds can change with government policy, so this should be treated as an estimate.

Common mistakes to avoid

  • Forgetting to budget for Stamp Duty Land Tax as an upfront cost separate from the deposit and mortgage.
  • Assuming the standard SDLT rate applies when buying an additional property or as a first-time buyer, when different rules apply in those cases.

Best practices

  • Always confirm current SDLT thresholds and any reliefs you may qualify for on gov.uk before relying on an estimate for a real transaction.

Tips

  • Scotland and Wales use different property transaction taxes (LBTT and LTT respectively) instead of SDLT — this calculator's stamp duty estimate applies to England and Northern Ireland only.

Frequently asked questions

Yes, with no signup and no limit on how many calculations you run.
SDLT thresholds and rates are set by the UK government and do change over time. This calculator uses the standard residential band structure for a single main home, without first-time-buyer relief or the additional-property surcharge — always verify current thresholds on gov.uk before a real purchase.
No — first-time buyers and second/additional properties are taxed under different rules (relief for first-time buyers, a surcharge for additional properties). This calculator shows the standard rate for a single main residence only.

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