Capital Gains Tax Calculator

Tax & Income Guide

How Capital Gains Tax works in the UK

Capital Gains Tax (CGT) is charged on the profit when you sell or dispose of an asset that has increased in value. It is the gain that is taxed, not the total proceeds. Selling shares for £30,000 that you bought for £20,000 creates a £10,000 gain, if that is above your annual exempt amount, only the excess is taxable. CGT is due for the tax year in which the disposal takes place, and for most assets is reported and paid via Self Assessment by 31 January the following year.

Rates and the annual exempt amount

For 2026/27 the annual CGT exempt amount is £3,000. Gains below this threshold are tax-free each year, but it cannot be carried forward, so any unused exemption is lost at 5 April. Above the exemption, gains are taxed at rates that depend on whether you are a basic or higher-rate taxpayer and on the type of asset:

Gains are stacked on top of your taxable income to determine which rate applies. A gain that straddles the basic and higher-rate band is split, with the portion below the higher-rate threshold taxed at 18% and the rest at 24%.

What is exempt from CGT?

Your main home is usually exempt through Private Residence Relief. Assets held in an ISA or pension are completely sheltered. Gifts between spouses or civil partners do not trigger CGT at the time of transfer, the recipient inherits the original acquisition cost. Other exemptions include:

• Premium Bonds, government gilts, and qualifying corporate bonds
• SAYE (Save As You Earn) and Share Incentive Plan shares (within limits)
• Personal belongings (chattels) sold for £6,000 or less, above that, only the gain over £6,000 is taxable
• Cars (including classic cars), all private vehicles are exempt regardless of gain
• Lottery and gambling winnings

The 60-day rule for property

Unlike other assets, where you report gains via Self Assessment by 31 January, residential property disposals have a much tighter deadline. If you sell a UK residential property that attracts CGT (i.e. it is not your main home, or only partially exempt), you must report the gain and pay the estimated tax within 60 days of completion. This is done through HMRC's online UK Property Reporting Service.

Missing the 60-day deadline triggers automatic late-filing penalties starting at £100, plus interest on unpaid tax. You still report the disposal on your Self Assessment return to reconcile the final figure, the 60-day payment is an estimate based on in-year tax.

Business Asset Disposal Relief (BADR)

Formerly known as Entrepreneurs' Relief, BADR reduces the CGT rate to 10% on qualifying gains from disposing of a business or business assets, up to a lifetime limit of £1 million of qualifying gains (reduced from £10m in 2020). To qualify, you typically need to have owned the business for at least two years and held at least 5% of shares and voting rights in the company. BADR is claimed through your Self Assessment return and can save significant amounts when selling a business compared to the standard higher-rate 24%.

CGT on crypto assets and NFTs

HMRC treats cryptocurrency (Bitcoin, Ethereum, and other tokens) as a capital asset, not currency. Every disposal, whether selling for cash, swapping one token for another, using crypto to buy goods, or gifting it to someone other than a spouse, is a taxable event. Each transaction creates a gain or loss based on the market value in sterling at the time of disposal versus your acquisition cost. NFTs are similarly treated as capital assets.

Crypto losses can be offset against other capital gains in the same year or carried forward to future years, but you must report them to HMRC within four years. HMRC has access to data from many UK and international exchanges and has sent nudge letters to crypto holders it believes have unreported gains.

Reducing your CGT bill legally

Use your annual exempt amount every year, it cannot be carried forward, so unused allowance is permanently lost each April. Beyond that, the most effective strategies are:

• Bed-and-ISA: sell assets outside an ISA and immediately repurchase them inside one. Future growth is then completely sheltered from CGT. The 30-day share-matching rule does not apply to ISA repurchases.
• Spouse transfers: transferring assets to a spouse or civil partner before sale uses their exempt amount and potentially their lower tax rate.
• Stagger disposals: splitting a large gain across two tax years uses two years' worth of the £3,000 exemption.
• Offset losses: capital losses in the same year reduce your net gain. Report losses even when you have no gains, they can be carried forward indefinitely.
• EIS/SEIS deferral: investing gains into qualifying Enterprise Investment Scheme shares can defer CGT, and SEIS investments can give a 50% CGT reinvestment relief.