Capital Gains Tax Calculator 2026-27

Capital Gains Tax (CGT) is charged on the profit you make when you sell or dispose of an asset that has increased in value. For the 2026/27 tax year, the annual exempt amount is £3,000. Gains above that are taxed at 18% where they fall inside your remaining basic rate band and 24% where they sit above it, so the amount of unused band you have decides the rate. A £25,000 gain on shares for a higher-rate taxpayer leaves £22,000 taxable once the exemption is deducted, and 24% of that is £5,280.

Since 30 October 2024 all asset types are taxed at the same rates. Residential property, shares, crypto and business assets now share the 18% and 24% figures, and the previous 10% and 20% rates for non-property assets no longer apply. Business Asset Disposal Relief moved in the same direction, rising from 10% before April 2025 to 14% in 2025/26 and 18% in 2026/27, although the £1m lifetime limit stays where it was.

That £3,000 exemption has shrunk sharply from the £12,300 available in 2022/23, which pulls many more disposals into charge than used to be the case. Each person has their own, so a married couple or civil partners holding an asset jointly can use £6,000 in a year. It cannot be carried forward, so an unused allowance is simply lost. Bed and spousing, where one partner sells and the other buys back an identical holding, uses the seller's own allowance without the 30-day matching rule applying, so the household keeps the investment. A transfer to a spouse is made at no gain, no loss, which means the partner's own annual exempt amount is used only when they later sell the part they received. Bed and ISA realises a gain within the exemption while sheltering future growth.

A disposal is broader than a sale. It covers gifting, except to a spouse or a charity, exchanging one asset for another, including crypto-to-crypto trades, and receiving compensation for a damaged or lost asset. Death is not a disposal, and assets take a capital gains uplift to market value at that point. Transfers between spouses happen on a nil-gain, nil-loss basis. For crypto specifically, spending it on goods, swapping ETH for BTC and earning yield all count, and under the OECD Crypto-Asset Reporting Framework UK cryptoasset service providers have collected user and transaction data since 1 January 2026, with the first reports due to HMRC by 31 May 2027.

Your main home is usually exempt under Private Residence Relief, and losses from other disposals in the same or previous tax years can be offset against gains before tax is calculated. Full relief needs the property to have been your main residence throughout ownership, with time-apportioned relief for periods of absence, and the final 9 months always count even after you have moved out. Tighter rules apply where you lived somewhere briefly then let it, since Letting Relief is now restricted to shared-occupancy lets. With more than one home, a PPR election within 2 years of acquiring the second nominates which counts as the main residence.

Most CGT is reported through Self Assessment by 31 January following the end of the tax year. UK residential property is the exception and must be reported within 60 days of completion using the gov.uk Capital Gains Tax on UK Property service. Late filing brings £100 straight away, then daily £10 penalties after 3 months, plus interest. If you would rather not wait for the year-end return, the Real Time service lets you report and pay non-property gains as they arise.

Crypto and share disposals are matched under the Section 104 pooling rules rather than by simple first in, first out. Anything bought and sold on the same day is matched first, then against purchases made in the following 30 days, which closes off the old bed-and-breakfasting trick, and only then against the pool holding the average cost of everything bought earlier. Most exchanges do not track pooling, so specialist software such as Koinly, Recap or CoinTracker is the practical answer for anyone with more than a handful of trades.