UK Stamp Duty Calculator (SDLT)

Stamp Duty Land Tax is the single most misunderstood cost in an England or Northern Ireland property purchase, and the misunderstanding is almost always the same one: buyers assume the tax due is their purchase price multiplied by one rate. It is not. SDLT is a sliced, progressive tax — the same mechanic income tax uses — where each band of the price is taxed at its own rate, and only the portion of the price that falls inside that band is taxed at it.

For someone moving home and replacing their main residence, the current bands (in force since 1 April 2025) are 0% up to £125,000, 2% on the slice from £125,001 to £250,000, 5% from £250,001 to £925,000, 10% from £925,001 to £1.5 million, and 12% above that. A £350,000 purchase is not taxed at a single rate — it pays 0% on the first £125,000, 2% on the next £125,000 (£2,500), and 5% on the remaining £100,000 (£5,000), for a total of £7,500. None of the lower-band saving disappears once a buyer crosses into a higher band.

First-time buyers get a more generous version of the same slicing: 0% up to £300,000 and 5% from £300,001 to £500,000. The trap is what happens beyond that upper limit. Relief is not tapered away — it disappears entirely the moment the price exceeds £500,000, and the whole purchase reverts to the standard bands above. A first-time buyer paying exactly £500,000 owes £10,000; a first-time buyer paying £600,000 owes £20,000, identical to what a home mover would pay at the same price, with none of the relief that applied at £500,000. Missing this cliff by even a small margin is a common and expensive surprise.

Buying an additional residential property — a second home, holiday home, or buy-to-let — adds a surcharge on top of the standard bands: 5 percentage points on every band, including the one that is normally 0%. So the bands for an additional property become 5%, 7%, 10%, 15%, and 17% instead of 0%, 2%, 5%, 10%, and 12%. This surcharge rose from 3 percentage points to 5 from 31 October 2024. Because it applies uniformly across every band, the total tax for an additional property always works out to the standard-rate tax plus 5% of the full purchase price — on £350,000, that is £7,500 plus £17,500, for a total of £25,000. The surcharge does not apply at all if the price is below £40,000.

If the new purchase is genuinely a replacement of a main residence and the previous main residence has already sold, the surcharge does not apply at all — that belongs in the home mover category above. If the old home has not sold yet at the time of the new purchase, the surcharge is charged upfront and can be reclaimed once the old home sells, provided the sale completes within 3 years (36 months) of buying the new property.

This calculator only covers Stamp Duty Land Tax as it applies in England and Northern Ireland. Scotland replaced SDLT with its own Land and Buildings Transaction Tax (LBTT) in 2015, and Wales replaced it with Land Transaction Tax (LTT) in 2018 — both are separate devolved taxes with their own bands, rates, and first-time buyer rules that do not match the figures here. Running a Scottish or Welsh purchase through this calculator will give the wrong answer. This calculator also does not include the separate 2% surcharge that applies to non-UK residents buying residential property in England or Northern Ireland, which stacks on top of everything above.

Every figure here reflects the England and Northern Ireland SDLT rates confirmed directly against GOV.UK on 19 August 2026. Rates and bands move with the Budget — the current bands only took effect on 1 April 2025, replacing a temporarily higher nil-rate threshold, and the additional property surcharge itself changed as recently as October 2024. Treat this as a planning estimate rather than a completion statement, and confirm the exact figure with your conveyancer or HMRC before exchanging contracts.