How it works
What this calculadora actually does
The Capital Gains Tax Estimator (UK) works out your capital gains tax calculator UK in seconds, using the 2026 figures most UK households actually check against.
A capital gains tax calculator UK sounds simple until the edge cases show up. Capital Gains Tax Estimator (UK) handles both the common case and the awkward ones — and labels which is which on screen.
Lenders model this scenario with the same tools — no reason you should be in the dark. Think of the next 12 months in whole pounds or reais, not percentages — then run the sums and the rest of this page explains what the answer means.
CGT applies when you sell or give away chargeable assets above the annual exempt amount. Rates depend on total taxable income: for non-property gains, basic-rate taxpayers typically pay 10% on gains within the basic-rate band and 20% above; residential property carries 18%/28% bands. Always verify current thresholds on GOV.UK.
On this page you will see Personal Finance, GOV.UK and HMRC treated as first-class terms — each one is linked to the calculators and references that use it, so you can follow the thread without retyping queries into a search bar.
If it helps, jump straight to the Finance hub or compare with the ISA Allowance Calculator (UK) and the Stamp Duty Calculator (SDLT) — those two calcs are the ones readers usually open right after this page.
A sample run with everything shown
The quickest way to sanity-check any formula is to try it on figures you recognise. Try these:
A basic-rate taxpayer sells shares they bought for £10,000 at £18,000. The gain is £8,000. After the 2024/25 annual exempt amount of £3,000 the taxable gain is £5,000, taxed at 10% = £500 CGT.
A higher-rate taxpayer sells a buy-to-let flat for £320,000 that they bought for £210,000. Gain of £110,000, less £5,000 of allowable costs (legal fees, estate agent) = £105,000. After the £3,000 exempt amount, £102,000 is taxed at 28% = £28,560 CGT, payable within 60 days via a UK Property CGT return.
Scenarios where Capital Gains Tax Estimator (UK) pays off
Capital Gains Tax Estimator (UK) is aimed at people arriving with questions like these:
- "CGT annual exemption"
- "Capital gains tax rates UK"
- "CGT on shares"
- "Higher rate CGT"
- "What is capital gains tax calculator uk"
- "How to calculate capital gains tax calculator uk"
When it isn't the right tool
Every tool has an edge where it stops being the right answer. Capital Gains Tax Estimator (UK) is no exception:
- For legally binding tax or medical decisions — cross-check with HMRC, NHS or a qualified professional.
- For very large or very small extremes the rounding error outgrows the useful precision.
- When the underlying rate or threshold has changed since the page was last reviewed — always verify with the primary source.
- When the input you have is already a derived figure (net of something) — feeding it in as "gross" will double-subtract.
Mistakes we see over and over
Every time you run the sums for a new scenario, one of these creeps in — it's worth knowing them ahead of time.
- Forgetting the 60-day CGT return for UK residential property — miss it and HMRC charges penalties and interest regardless of whether you owe tax.
- Assuming your main home is always exempt. Private Residence Relief only covers the period you lived in it; a letting period (even if you moved out years ago) creates a chargeable portion.
- Ignoring allowable costs. Legal fees, stamp duty paid at purchase, estate-agent commission and the cost of capital improvements all reduce the gain. Keep the receipts for 5 years after the tax year of disposal.
- Treating all gains equally. Residential property, carried interest and other specified gains pay higher rates than generic non-property gains — read Schedule 1A to TCGA 1992 before simulating.
The sources behind the numbers
Where the maths needs an external authority, we cross-check against:
- GOV.UK
- HMRC
Works well alongside
If this question keeps coming up for you, the same cluster of tools usually comes next:
- ISA Allowance Calculator (UK) — Track use of the annual £20,000 ISA subscription limit across Cash and Stocks & Shares ISAs, and see how much headroom you have before the tax year ends.
- Stamp Duty Calculator (SDLT) — Work out Stamp Duty Land Tax on a UK property purchase — first-time buyer, main residence or additional property — for England and Northern Ireland.
- UK Income Tax Calculator — Calculate Income Tax on your UK earnings across the basic, higher and additional rate bands, with the personal allowance applied automatically.
- Dividend Tax Calculator (UK) — Work out income tax on dividends above the Dividend Allowance at basic, higher and additional rates — including typical director/shareholder scenarios for UK limited companies.
How we keep this accurate
Our calculadoras run on pure, unit-tested functions — the same logic lives in the browser and in the CI test suite. When tax rates, thresholds or official figures move, the update lands within 24 hours of the announcement. You can read the editorial policy and corrections policy.
Found an out-of-date number on Capital Gains Tax Estimator (UK) or anywhere else in the Finance toolkit? Send it to the editorial desk and we'll patch it. Or browse the full calculadora directory for the next tool you need.
