Calculate Your SDLT in Seconds
Use this UK stamp duty calculator for residential purchases in England and Northern Ireland.
This tool is for guidance only and uses commonly applied residential SDLT assumptions. Always confirm with HMRC or a qualified solicitor before exchanging contracts.
What is Stamp Duty Land Tax (SDLT)?
Stamp Duty Land Tax is the tax paid when you buy property or land above a certain price threshold in England and Northern Ireland. It applies to freehold and leasehold purchases, whether you buy outright or with a mortgage.
The key point many buyers miss: SDLT is a progressive tax. You do not pay one flat percentage on the entire purchase price. Instead, each slice of the price is taxed at its own rate band.
How SDLT bands work
Think of SDLT like income tax bands. For each band, only the amount that falls inside that band gets taxed at that rate.
Standard residential rates (used by this calculator)
| Portion of property price | SDLT rate |
|---|---|
| Up to £125,000 | 0% |
| £125,001 to £250,000 | 2% |
| £250,001 to £925,000 | 5% |
| £925,001 to £1,500,000 | 10% |
| Above £1,500,000 | 12% |
First-time buyer relief (used by this calculator)
- 0% on the first £300,000
- 5% on the portion from £300,001 to £500,000
- If the price is above £500,000, standard rates apply to the full price
Surcharges included
- Additional property surcharge: +5% of the full purchase price
- Non-UK resident surcharge: +2% of the full purchase price
How to use this stamp duty land tax calculator
- Enter the purchase price of the property.
- Select whether you are a standard buyer or first-time buyer.
- Tick the additional property and/or non-resident boxes if they apply.
- Click Calculate SDLT to view total tax and a full breakdown.
Example calculations
Example 1: Standard buyer purchasing at £300,000
Tax is calculated in slices:
- £0 to £125,000 at 0% = £0
- £125,001 to £250,000 at 2% = £2,500
- £250,001 to £300,000 at 5% = £2,500
Total SDLT: £5,000
Example 2: First-time buyer at £425,000
- £0 to £300,000 at 0% = £0
- £300,001 to £425,000 at 5% = £6,250
Total SDLT: £6,250
Example 3: Additional property at £400,000
You pay normal SDLT plus the 5% surcharge on the full amount. This can significantly increase your total tax bill, so planning cash flow ahead of completion is essential.
Common SDLT mistakes buyers make
- Assuming one flat rate applies to the full purchase price.
- Forgetting to budget for second-home surcharge.
- Not checking if first-time buyer relief still qualifies based on purchase price.
- Ignoring special cases like mixed-use property, companies, or lease premiums.
- Leaving tax planning too late in the conveyancing process.
Final thoughts
A good stamp duty calculator helps you estimate total buying costs before you make an offer. SDLT can materially impact deposit needs, mortgage affordability, and your overall investment return. Use this tool early in your property search, then confirm exact figures with your solicitor before completion.