Capital Gains Tax calculator

How Capital Gains Tax is worked out

Your gain is the sale price minus what you paid and your allowable costs: the costs of buying and selling, such as solicitors' and estate agents' fees, and money spent improving the asset, such as an extension. Normal maintenance like decorating does not count.

Take any losses and the £3,000 annual exempt amount off the gain. What is left is your taxable gain.

The rate depends on your income in the same tax year. Your taxable income is your income minus your Personal Allowance of £12,570, which shrinks by £1 for every £2 of income over £100,000. The taxable gain is added on top. The part that fits in the £37,700 basic rate band is taxed at 18% and the rest at 24%.

On £30,000 of income, taxable income is £17,430, which leaves £20,270 of the basic rate band. A £25,000 gain is £22,000 after the allowance: £20,270 is taxed at 18% and £1,730 at 24%, a total of £4,064.

Capital Gains Tax uses the UK basic rate band of £37,700 for everyone, Scottish taxpayers included, so the calculation is the same across the UK.

Capital Gains Tax rates since 30 October 2024

Since 30 October 2024 the same rates apply to every type of asset, residential property included. For 2026/27:

Gains	Rate
Within your unused basic rate band	18%
Above the basic rate band	24%
Qualifying for Business Asset Disposal Relief	18%
Qualifying for Investors' Relief	18%
Made by trustees and personal representatives	24%

Business Asset Disposal Relief rose from 14% in 2025/26 to 18% for disposals on or after 6 April 2026. It still matters once your gains pass the basic rate band, because qualifying gains stay at 18% where other gains pay 24%. On a £400,000 gain from selling a business, someone earning £60,000 pays £71,460 with the relief and £95,280 without it. Both reliefs have a lifetime limit of £1,000,000 of gains.

The £3,000 annual exempt amount

The first £3,000 of your total gains each tax year is tax-free. Most trusts get £1,500. The allowance covers all your gains in the year together, so if other sales have already used it, choose "Used on other gains" in the calculator.

When some gains are taxed at 18% and some at 24%, you can set the allowance against the ones that would pay 24%. The calculator does this for you.

Selling your main home

You usually pay no Capital Gains Tax when you sell your main home, because Private Residence Relief covers it. GOV.UK explains when the relief applies in Tax when you sell your home. This calculator is for property that was not your main home, such as a buy-to-let or a second home.

Reporting a property gain within 60 days

If you are a UK resident and sell a UK residential property with Capital Gains Tax to pay, you must report the sale and pay the tax within 60 days of completion. You do this through HMRC's Capital Gains Tax on UK property service. If you also file a Self Assessment return, you include the sale there too.

On a £100,000 gain, that means paying £22,064 within 60 days if you earn £30,000, or £23,280 if you earn £60,000. The 60-day deadline applies to UK residential property, so gains on shares and other assets do not have it.

Ways to pay less Capital Gains Tax

• Use the allowance every tax year. The £3,000 allowance belongs to one tax year and does not carry over. If you can sell in parts, such as a holding of shares, selling some before 6 April and the rest after uses two allowances.
• Time gains for a lower-income year. The rate depends on your income in the tax year you sell, so more of a gain is taxed at 18% in a year when your income is lower. On £30,000 of income, a £50,000 gain taken in one tax year costs £10,064. Split evenly over two tax years with the same income in each, it costs £8,128.
• Transfer to a spouse or civil partner. You pay no Capital Gains Tax on assets you give to your husband, wife or civil partner, unless you were separated and did not live together at all in that tax year. The asset becomes theirs. When they sell, they pay tax on the gain since you first bought it, using their own allowance and income. Someone earning £60,000 pays £11,280 on a £50,000 gain. If they give half to a partner earning £30,000 first, the couple pays £9,344 between them.
• Use your losses. Report losses to HMRC so they can be set against your gains. Losses from the same tax year come off first. Losses from earlier years only bring your gains down to the £3,000 allowance, so the allowance is never wasted, and the rest carries forward.