Capital Gains Tax Allowance Calculator 2026/27

What is the CGT annual exempt amount (and why it matters now)?

The annual exempt amount — often just called the Capital Gains Tax allowance — is the amount of net capital gains an individual can realise in a tax year before any CGT becomes payable. For 2026/27 it is £3,000, the same as 2025/26 and 2024/25. Crucially, this is a fraction of what it used to be: the allowance was £12,300 as recently as 2022/23, was cut to £6,000 for 2023/24, and was then halved again to £3,000 from 6 April 2024. That 75% reduction in three years is the single biggest reason far more ordinary investors and landlords now find themselves with a CGT bill.

Capital Gains Tax applies to the profit when you sell or otherwise dispose of an asset that has risen in value — not the whole sale price. Common chargeable assets include shares and funds held outside an ISA or pension, a second home or buy-to-let property, business assets, and personal possessions worth more than £6,000 (excluding your car). You only pay CGT on total gains above the allowance, so the calculator above first subtracts the £3,000 to give your taxable gain, then applies the relevant rate.

The allowance is per person, per tax year, and it cannot be carried forward. Married couples and civil partners each have their own £3,000, and assets can usually be transferred between spouses with no CGT (a "no gain, no loss" transfer), which means a couple can shelter up to £6,000 of gains between them and use two sets of basic-rate bands. Using the allowance every year, and spreading larger disposals across more than one tax year (a strategy sometimes called "bed and ISA" or simple staggering), is now central to keeping CGT down.

CGT rates 2026/27: 18% and 24%, and how your income decides which

Following the 30 October 2024 Budget, the main rates of Capital Gains Tax for individuals were aligned. For disposals on or after 6 April 2026 the rates are:

• 18% on the part of your taxable gain that falls within your remaining basic-rate Income Tax band; and
• 24% on the part of your taxable gain above the basic-rate threshold (i.e. for higher and additional-rate taxpayers).

Importantly, these same 18% / 24% rates now apply to both residential property and other assets such as shares. Before the change, residential property gains were taxed at a higher 18% / 24% scale while other assets sat at 10% / 20%; the lower 10% / 20% rates were increased to 18% / 24% so that all asset types are now aligned. There is no longer a separate, higher rate for second homes and buy-to-lets — the rate depends on your income band, not the type of asset.

Why does your taxable income matter? Capital gains are effectively stacked on top of your income to decide the rate. The basic-rate band for Income Tax runs up to £50,270 of taxable income (after the £12,570 Personal Allowance). If your income uses, say, £35,000 of that band, you have roughly £15,270 of "room" left, so the first £15,270 of your taxable gain is taxed at 18% and anything above that at 24%. This is exactly the calculation the tool above performs — it works out how much of the basic-rate band you have left and splits the gain accordingly, which is why two people with the same gain can owe very different amounts of CGT.

Business Asset Disposal Relief (BADR) remains for qualifying business sales, taxed at 18% up to a £1 million lifetime limit (the BADR rate rose from 10% to 14% in 2025/26 and to 18% from 6 April 2026). Trustees and personal representatives pay a flat 24%. Rates verified against GOV.UK — CGT rates.

Reporting and paying CGT: the 60-day property deadline

How and when you report a gain depends on the asset:

UK residential property (60-day rule). If you sell a second home or buy-to-let and there is a taxable gain, you must report it and pay the CGT due within 60 days of completion, using a dedicated "Capital Gains Tax on UK property" account at GOV.UK. This deadline applies even if you normally file a Self Assessment return — you report through the property account first and then again on your annual return. Missing the 60-day deadline triggers automatic penalties and interest.

Shares and other assets. For most other gains you report through your Self Assessment tax return for the relevant tax year (deadline 31 January after the end of the tax year), or you can use HMRC's "real-time" CGT service to report and pay sooner. You must report if your total gains exceed the £3,000 allowance, or if your total proceeds (the amount you sold for, not the gain) exceed £50,000 in the tax year, or if you already file a Self Assessment return — even where no tax is due.

Do you report gains under the allowance? Generally no — if your total gains are below £3,000, your proceeds are under the £50,000 limit, and you don't otherwise need to complete a return, there is nothing to report. But keep records of every disposal (dates, costs, proceeds), because HMRC can ask for them and you may need them to prove a gain was within the allowance.

Worked example: £20,000 gain on shares for a basic-rate taxpayer

Suppose Priya sells shares (held outside an ISA) in 2026/27 and makes a £20,000 gain. Her taxable income for the year is £35,000 (after her Personal Allowance), and she has used none of her allowance yet. Here is how the calculator works it out:

Priya pays £3,163.80 in CGT and keeps £16,836.20 of her £20,000 gain. Her effective rate on the taxable gain is about 18.6%. Note how most of the gain falls in the 18% band because her income left plenty of basic-rate room — a higher-rate taxpayer making the same gain would pay 24% on the whole £17,000 (£4,080). Under the old £12,300 allowance, only £7,700 would have been taxable, showing how much the allowance cut has increased real CGT bills.

How to legally reduce your Capital Gains Tax

With the allowance now just £3,000, planning matters more than ever. Common, legitimate ways to reduce CGT include:

Use both spouses' allowances. Transfers between married couples and civil partners are made on a "no gain, no loss" basis, so moving an asset (or part of it) to a partner before sale can use two £3,000 allowances and two sets of basic-rate bands — often saving thousands.

Spread disposals across tax years. Because the allowance resets each 6 April and cannot be carried forward, selling part of a holding in March and part in April uses two years' allowances. The calculator's "allowance already used" field lets you model a second disposal in the same year.

Use your ISA and pension wrappers. Gains on investments held inside a Stocks & Shares ISA or a pension are completely free of CGT. "Bed and ISA" — selling holdings and immediately repurchasing them inside an ISA — shelters future growth, using the £20,000 annual ISA allowance.

Offset losses. Capital losses on other assets are deducted from your gains before the allowance is applied, and unused losses can be carried forward indefinitely if you report them to HMRC within four years. This is one of the most overlooked CGT savings, especially for share investors.