Capital gains tax calculator

How the capital gains tax calculator works

Capital Gains Tax (CGT) is charged on the profit you make when you sell, or give away, something that has gone up in value. It's the gain that's taxed, not the sale price. This calculator works out your gain, takes off your tax-free allowance and any losses, and then uses your income to decide how much of the gain is taxed at 18% and how much at 24%. All figures are for the 2026/27 tax year, from 6 April 2026 to 5 April 2027.

Capital gains tax rates for 2026/27

Since 30 October 2024 the same 18% and 24% rates apply to property and to other assets, so the choice in the calculator only changes the reporting rules. The allowance has been £3,000 since April 2024, down from £6,000 in 2023/24 and £12,300 before that. One change for 2026/27 is that Business Asset Disposal Relief has risen from 14% to 18%, the same as the basic CGT rate.

How your income decides the rate

Your taxable gain is added on top of your taxable income (income minus your £12,570 Personal Allowance). Any part of the gain that fits within the £37,700 basic rate band is taxed at 18%, and the rest at 24%. If you're already a higher or additional rate taxpayer, the whole gain is taxed at 24%. Scottish taxpayers use these UK bands for CGT, not the Scottish income tax bands.

Relief-at-source pension contributions and Gift Aid donations extend your basic rate band by the gross amount, so a well-timed pension payment can move part of a gain from 24% down to 18%.

Worked example: selling shares

You bought shares for £10,000 and sell them for £30,000, a gain of £20,000. Your salary is £40,000.

• Taxable gain: £20,000 − £3,000 = £17,000
• Taxable income: £40,000 − £12,570 = £27,430, leaving £10,270 of the basic rate band
• £10,270 at 18% = £1,848.60
• £6,730 at 24% = £1,615.20
• Total Capital Gains Tax: £3,463.80

HMRC's own example uses £20,000 of taxable income and £52,600 of gains. After the £3,000 allowance, £17,700 is taxed at 18% and £31,900 at 24%, giving £10,842. Enter £32,570 income and a £52,600 gain to see the same answer here.

Worked example: selling a buy-to-let

A higher rate taxpayer earning £60,000 sells a rental flat for £300,000. They paid £200,000 and spent £5,000 on legal fees and stamp duty. The gain is £95,000, the taxable gain after the allowance is £92,000, and all of it is taxed at 24%: £22,080, due within 60 days of completion.

What you can deduct from a gain

• Costs of buying and selling: broker fees, stamp duty, solicitor and estate agent fees
• Improvements that add value, such as an extension or new kitchen (but not repairs or redecoration)
• Capital losses from the same year, then losses brought forward from earlier years. Brought-forward losses are only used to bring the gain down to the £3,000 allowance, so the rest carries forward

Tips to pay less capital gains tax

• Use both allowances: transfers between spouses and civil partners are tax-free, so a couple can use two £3,000 allowances and two basic rate bands.
• Spread sales across tax years: selling half before 5 April and half after gives you two allowances.
• Bed and ISA: move shares into a stocks and shares ISA each year so future gains are tax-free.
• Report losses: you must tell HMRC about a loss within four years to be able to use it later.

Investment income is taxed separately: see the dividend tax calculator, and the income tax calculator to check your taxable income. Planning ahead for an estate? Try the inheritance tax calculator.

Last reviewed October 2026 using 2026/27 figures. This calculator gives an estimate for guidance only.