Estimate UK Capital Gains Tax owed after the annual exempt amount, based on your income tax band.
Everyone has a tax-free Capital Gains Tax allowance (the annual exempt amount) each year. Gains above that are taxed at 18% if you're a basic-rate taxpayer or 24% if you're a higher/additional-rate taxpayer (rates shown are for most assets excluding residential property, which has its own rates).
Illustrative estimate only, using simplified/rounded 2026/27 UK figures — not tax advice. Always confirm with HMRC or a qualified UK tax adviser.
Capital Gains Tax applies to profit made when you dispose of an asset that has increased in value — shares outside an ISA, a second property, or business assets are the most common triggers. For 2026/27 the annual tax-free allowance is £3,000 per person, well down from the £12,300 it stood at a few years ago, which means far more routine disposals now generate a CGT bill than in the past. Gains above the allowance are taxed at 18% for basic-rate taxpayers and 24% for higher and additional-rate taxpayers, with the same two rates applying whether the asset is shares, a second home, or most other chargeable property.
Your main home is normally exempt under Private Residence Relief, provided it has been your only or main residence throughout ownership. Losses can be set against gains in the same tax year, and unused losses can be carried forward indefinitely to offset future gains, which is worth tracking even in years with no disposals.
No. Growth inside an ISA or a pension wrapper is shielded from Capital Gains Tax entirely, which is one of the main reasons ISAs and pensions are the default recommendation for long-term investing in the UK before using a general investment account.
Within 60 days of completion, using HMRC's dedicated online CGT-on-UK-property return, separately from your annual Self Assessment. Missing that window can trigger penalties even if the tax itself is eventually paid correctly.
No, it does not carry forward — an unused allowance is lost at the end of the tax year. That is why some investors deliberately realise gains up to the allowance most years rather than letting several years of gains stack into one.
Generally yes — HMRC treats most cryptoasset disposals as subject to Capital Gains Tax in the same way as shares, using the same annual allowance and the same 18%/24% rates, though the record-keeping burden is often higher given the volume of transactions many crypto holders make.