Capital Gains Tax Calculator UK 2026: Rates, Allowance and Worked Examples

HMRC collected a record capital gains tax haul in the last full tax year, and the number of people caught by the charge keeps climbing. The reason is simple. The annual tax free allowance for capital gains has been cut from £12,300 to just £3,000 in the space of three years, so a modest share sale, a crypto disposal or the sale of a second property can now create a bill where none existed before. If you have sold an asset in the 2026/27 tax year and you are trying to work out what you owe, this guide walks you through it.

Below you will find the current UK capital gains tax rates, the annual exempt amount, a step by step method for calculating your gain, worked examples for shares and for property, the reliefs that reduce your bill, and the deadlines for reporting and paying. All figures relate to the 2026/27 tax year unless stated otherwise, and you should always confirm the latest position on GOV.UK before filing.

What capital gains tax actually is

Capital gains tax is charged on the profit you make when you dispose of an asset, not on the amount you receive for it. Dispose means sell, give away, swap or receive compensation for. If you bought shares for £8,000 and sold them for £14,000, the £6,000 profit is the gain. The £14,000 is not.

Assets that fall inside the CGT net include shares held outside an ISA or pension, second homes and buy to let property, business assets, cryptoassets such as Bitcoin, valuable personal possessions worth more than £6,000, and most units in funds. Assets outside the net include your main home in most cases, cash in sterling, ISA holdings, pension savings, premium bonds, UK government gilts, and personal cars.

Capital gains tax is completely separate from income tax, but the two interact. The size of your salary determines which CGT rate applies, which is why anyone doing this calculation needs to know their taxable income first. If you are not sure what your taxable income is, our guide to reading a UK payslip explains where to find the numbers.

UK capital gains tax rates for 2026

The main rates were increased at the October 2024 Budget and have applied since. For the 2026/27 tax year the position is as follows.

Business Asset Disposal Relief, which many people still call Entrepreneurs Relief, has been rising in stages. It moved to 14% in April 2025 and to 18% from 6 April 2026, with a £1 million lifetime limit on qualifying gains. If you are planning a business sale, the timing matters a great deal and professional advice is worth the fee.

The annual exempt amount

Every individual has an annual exempt amount, which is the slice of gains you can make each year before any tax is due. It stands at £3,000. Trusts generally get half of that, at £1,500.

Three points catch people out. The allowance covers your total gains across all assets in the year, not each asset separately. It cannot be carried forward, so if you do not use it by 5 April it is gone. And it applies per person, which means a married couple or civil partners who own an asset jointly have £6,000 of combined allowance to work with.

How to calculate capital gains tax step by step

Work through these five steps in order.

1. Start with the disposal proceeds, which is what you sold the asset for. If you gave it away or sold it below market value to a connected person, use the open market value instead.
2. Deduct the acquisition cost, meaning what you originally paid for it, or its probate value if you inherited it.
3. Deduct allowable costs. For property this includes stamp duty, legal fees, survey fees, estate agent fees and the cost of capital improvements such as an extension. For shares it includes broker commission and stamp duty reserve tax. Routine maintenance, mortgage interest and insurance are not allowable.
4. Deduct any capital losses. Losses from the same tax year must be used in full. Unused losses from earlier years can be brought forward, but only enough to bring you down to the annual exempt amount.
5. Deduct the £3,000 annual exempt amount. What remains is your taxable gain.

Then work out the rate. Add your taxable gain to your taxable income for the year. Any part of the gain that falls within the basic rate band, which runs to £50,270, is taxed at 18%. Any part above that threshold is taxed at 24%.

Worked example one: selling shares

Priya earns £38,000 a year. After her £12,570 personal allowance, her taxable income is £25,430, which leaves £24,840 of basic rate band unused. She sells shares for £30,000 that she bought for £16,000, paying £150 in broker fees across both transactions.

Her gain is £30,000 minus £16,000 minus £150, which is £13,850. She deducts the £3,000 annual exempt amount, leaving a taxable gain of £10,850. Because £10,850 fits comfortably inside her remaining basic rate band of £24,840, the whole gain is taxed at 18%. Her bill is £1,953.

Worked example two: selling a buy to let

Marcus earns £62,000, so he is already a higher rate taxpayer with no basic rate band left. He sells a rental flat for £245,000 that he bought for £180,000. His allowable costs are £3,600 of stamp duty on purchase, £1,400 in legal fees across both transactions, £3,900 in estate agent fees and £9,000 for a new extension.

His gain is £245,000 minus £180,000 minus £17,900 of allowable costs, which is £47,100. After the £3,000 exempt amount his taxable gain is £44,100. All of it sits in the higher rate band, so it is taxed at 24%, giving a bill of £10,584. Because this is UK residential property, Marcus must report and pay within 60 days of completion rather than waiting for his tax return.

Reliefs that cut your bill

Several reliefs can reduce or remove a capital gains charge.

• Private Residence Relief exempts the gain on your only or main home, including the final nine months of ownership even if you have moved out.
• Business Asset Disposal Relief applies an 18% rate to qualifying disposals of a trading business or of at least 5% of a trading company you work for, subject to a £1 million lifetime limit.
• Transfers between spouses and civil partners who live together happen at no gain and no loss, which lets couples use both annual allowances and both basic rate bands.
• Gift Holdover Relief can defer the gain on gifts of business assets and on transfers into certain trusts.
• Rollover Relief lets a business defer a gain when the proceeds are reinvested in new qualifying business assets.
• Gifts to registered charities and to your spouse are generally free of capital gains tax altogether.

How to report and pay

There are two routes, and using the wrong one is a common and expensive mistake.

For UK residential property, you must report the disposal and pay the tax within 60 days of completion using HMRC’s online Capital Gains Tax on UK property service. This applies even if you do not normally complete a self assessment return. Late filing penalties start at £100 and escalate.

For everything else, report the gain on the capital gains pages of your self assessment tax return. The deadline for online filing and payment for the 2026/27 tax year is 31 January 2028. HMRC also runs a real time capital gains service for people outside self assessment who want to settle a smaller gain straight away.

You need to report even when no tax is due if your total disposal proceeds exceed £50,000 and you already file a return, or if you want to register a capital loss for future use. Losses must be claimed within four years of the end of the tax year in which they arose.

Planning points worth knowing

Use the allowance every year rather than letting gains build up, because an unused annual exempt amount disappears on 5 April. Consider spreading a large disposal across two tax years so that two annual allowances and potentially two basic rate bands apply. Transfer assets to a lower earning spouse before sale where that is genuinely appropriate. Hold investments inside an ISA or pension wrapper where possible, since gains inside those wrappers are free of capital gains tax entirely. And keep every receipt, completion statement and broker note, because allowable costs are only deductible if you can evidence them.

If a change of job or a pay rise is about to push you from the basic rate into the higher rate band, the timing of a disposal can change your CGT rate from 18% to 24% on the same gain. Our guide to UK tax codes explains how HMRC tracks your income through the year, and you can browse current vacancies and salary levels on our UK jobs board.

Frequently asked questions

Do I pay capital gains tax when I sell my own home?
Usually not. Private Residence Relief normally covers the whole gain on your only or main residence, provided you have lived there throughout your ownership and the grounds are under half a hectare. Letting part of it out, using a room exclusively for business or owning more than one property can restrict the relief.

How much can I make before capital gains tax is due in 2026?
The annual exempt amount is £3,000 for individuals. Total net gains below that figure in a tax year carry no capital gains tax.

Do I pay capital gains tax on cryptocurrency?
Yes. HMRC treats most cryptoassets as chargeable assets, so selling crypto for pounds, swapping one token for another, or using crypto to buy goods all count as disposals. Share pooling rules apply in the same way they do for shares.

What is the deadline for paying capital gains tax on property?
Sixty days from completion for UK residential property, reported through HMRC’s dedicated property service. Other assets go on your self assessment return, due by 31 January following the end of the tax year.

Can I offset losses against my gains?
Yes. Losses in the same tax year are set against gains automatically. Losses carried forward from earlier years can be used, but only down to the level of the annual exempt amount, so you never waste the allowance. Report losses to HMRC within four years to preserve them.

Does capital gains tax count as income for my tax code?
No. Capital gains are taxed separately and do not change your personal allowance or your PAYE tax code. Your income does, however, determine whether the 18% or 24% CGT rate applies.