UK CGT Allowance Calculator
See the capital gains tax on your gains after the £3,000 annual allowance - and how much more you can realize tax-free before 5 April.
Estimate, not tax advice. Excludes carried-forward losses, other income affecting your band, and reliefs. Alvest tracks ISA/SIPP wrappers so sheltered holdings are excluded automatically.
UK capital gains tax - FAQ
What is the CGT annual allowance for 2024/25 and 2025/26?
The Capital Gains Tax annual exempt amount is £3,000 per person for 2024/25 and 2025/26. Gains up to this amount each tax year are tax-free; only gains above it are taxed.
When does the UK CGT allowance reset?
The allowance is per tax year, which runs 6 April to 5 April. It is use-it-or-lose-it - any unused allowance does NOT carry forward, so realizing gains up to £3,000 before 5 April can be tax-efficient.
What are the UK CGT rates?
For disposals on or after 30 October 2024, most assets are taxed at 18% (within the basic-rate band) or 24% (higher/additional rate). This calculator applies the band you select.
What is "Bed & ISA"?
Selling holdings in a general account and repurchasing them inside an ISA. This realizes gains (using your allowance) and moves the assets into a tax-free wrapper, so future gains and dividends are exempt. Alvest can track which holdings sit in your ISA vs your general account.
How is my cost basis calculated in the UK?
HMRC uses Section 104 pooling - the average cost of all shares of the same class, with same-day and 30-day "bed & breakfasting" matching rules first. Alvest applies exactly this, so your realized gain is correct (not simple FIFO).
How accurate is this estimate?
It applies the £3,000 allowance and the rate you pick, and is an estimate, not tax advice. It excludes losses carried forward, other income affecting your band, and specific reliefs. Confirm with your accountant.