UK Capital Gains Tax Calculator for Non-Residents

What the CGT calculator does and who it's for

This calculator estimates the UK Capital Gains Tax (CGT) you would owe on a single disposal — the sale of a UK residential or commercial property, UK shares or ETFs, or a business asset. It is built for the situation that catches out most people who have left the UK: a non-UK resident or returning expat who still holds a UK asset and needs a realistic figure before completing a sale. It works for UK residents too, but its real value is modelling the Non-Resident CGT (NRCGT) rules — rebasing, Private Residence Relief and the 60-day reporting deadline — that a generic calculator ignores. If you are weighing whether now is the right time to sell, or how a disposal sits alongside your wider affairs, start here and then explore the rest of our financial tools.

How the calculator works

The tool follows the same order HMRC uses to reach a chargeable gain. You enter the sale proceeds, the original purchase price, and the costs on each side — buying costs such as Stamp Duty, legal and survey fees, and selling costs such as agent and conveyancing fees — plus any spending on permanent capital improvements (not repairs or maintenance). It then computes:

• Gross gain = sale proceeds − selling costs − (purchase price + buying costs + improvements).
• Gain after reliefs = gross gain − any Private Residence Relief − the annual exempt amount.
• Estimated CGT = the taxable gain × the rate that applies to you.

The rate is chosen from your inputs. For individuals, residential and other assets are charged at 18% where the gain falls within the basic-rate band and 24% where you are a higher- or additional-rate taxpayer — the rates that have applied since the October 2024 Budget. Trusts are charged at the higher property rate, and companies are shown at the 25% corporation-tax rate, because a company pays Corporation Tax on chargeable gains rather than CGT. Your rough income band (the £12,570, £50,270 and £125,140 thresholds) decides whether the basic or higher rate bites.

NRCGT rebasing — the feature that matters for non-residents

Non-residents have only been within the UK CGT net since April 2015 for residential property and April 2019 for commercial property. So if you acquired the asset before those dates, you are generally taxed only on the growth after them, not on your entire ownership period. When the calculator detects a pre-2015 residential (or pre-2019 commercial) acquisition by a non-resident, it offers a rebasing option: enter the property's market value at the relevant rebasing date and the tool uses the higher of that value and your original cost as the base cost, so only post-rebasing gain is taxed. HMRC expects a defensible valuation — usually a RICS appraisal — to support the figure. Rebasing is optional; if the asset was worth less at the rebasing date than you paid, the original cost gives a better result and you can leave the box unticked.

Private Residence Relief and the annual exempt amount

If a residential property was once your main home, tick the PRR option and enter the months you lived there. The calculator relieves the fraction of the gain that corresponds to your period of occupation plus a final nine-month period that is always exempt, regardless of where you were living. Note that from April 2015 a non-resident must generally meet a day-count test in the property's country before an overseas tax year counts as occupation — so PRR is not automatic for expats. Whatever gain survives PRR is then reduced by the annual exempt amount (currently £3,000 for individuals and £1,500 for most trusts; companies receive none). Only the balance is taxed.

Reading your result — a worked example

Say a non-resident bought a UK flat in 2010 for £250,000, spent £5,000 buying it, and sells in 2025 for £400,000 with £8,000 of selling costs and no improvements. The gross gain is £400,000 − £8,000 − £255,000 = £137,000. With no PRR, the annual exempt amount of £3,000 leaves a taxable gain of £134,000. A higher-rate taxpayer pays 24%, giving an estimated CGT of roughly £32,160. If the flat was worth £310,000 at April 2015 and rebasing is elected, the base cost rises and the taxable gain — and the tax — fall sharply. The results panel shows each of these lines so you can see exactly where the number comes from, and it flags the 60-day reporting rule: a UK residential disposal must be reported and paid to HMRC within 60 days of completion, even when no tax is due.

Assumptions, limitations and what to do next

The estimate is deliberately simple. It applies a single flat rate rather than splitting a gain that straddles the basic-rate band, and it does not model capital losses brought forward, Business Asset Disposal Relief, Investors' Relief, or double-tax treaty relief in your country of residence — any of which can change the figure materially. It also assumes sterling throughout; if you think in another currency, exchange-rate movements between purchase and sale can create a gain (or loss) for HMRC that looks very different in your home currency. Because CGT rarely sits in isolation, it is worth checking your wider position: your UK residence status drives whether NRCGT even applies, your domicile and inheritance-tax exposure often move together with a property sale, and our tax planning hub puts the pieces together. For the letting side of UK property, the non-resident landlord guide covers the income-tax rules that run alongside CGT.