About the UK Capital Gains Tax Calculator
This UK capital gains tax calculator works out how much CGT you owe when you sell shares, funds, crypto, a buy-to-let or second home, or a business. Enter the sale price, what you paid, any buying, selling and improvement costs, and your taxable income for the year; it applies the annual exempt amount and splits the gain between the basic and higher rates.
It is designed for investors planning disposals before the tax year ends, landlords selling a rental property (who must report and pay within 60 days of completion), and business owners checking Business Asset Disposal Relief. Because CGT rates depend on how much of your basic-rate band your income has used, the tool also shows how much of the gain falls at each rate.
Rules used are for the 2026/27 tax year: a £3,000 annual exempt amount, 18% on gains within the £37,700 basic-rate band and 24% above it (the same rates now apply to shares and residential property), and 18% for gains qualifying for Business Asset Disposal Relief. The personal allowance of £12,570 tapers away above £100,000 of income. Your main home is usually exempt under Private Residence Relief.
With the default inputs, the capital gains tax due is £5,803.80. Change any value above to recalculate instantly.
How to use the uk capital gains tax calculator
- 1Choose the type of asset you sold.
- 2Enter your gross taxable income for the tax year.
- 3Enter the sale price, the original purchase price and allowable costs.
- 4Add any capital losses you can offset.
- 5Read the CGT due and how much of the gain is taxed at 18% and 24%.
Formula and method
The gain is the disposal proceeds minus the original purchase price and allowable costs such as broker or estate agent fees, legal fees, Stamp Duty Land Tax and capital improvements. Capital losses are deducted next, then the £3,000 annual exempt amount.
The taxable gain is added on top of your taxable income (income minus the personal allowance). Whatever part fits inside the £37,700 basic-rate band is taxed at 18% and the rest at 24%. Gains qualifying for Business Asset Disposal Relief are taxed at a flat 18% in 2026/27 up to the £1 million lifetime limit; any excess is taxed at the normal rates. The calculator assumes one disposal and that none of the annual exempt amount has been used on other gains this year.
- Band left
- £37,700 minus taxable income (never below zero)
- Costs
- Allowable acquisition, disposal and improvement costs
- £3,000
- Annual exempt amount for individuals, 2026/27
Worked examples
Selling shares with a £45,000 salary
The gain is £60,000 − £30,000 − £1,500 = £28,500, or £25,500 after the £3,000 allowance. A £45,000 salary uses £32,430 of the basic-rate band, leaving £5,270 taxed at 18% (£948.60) and £20,230 at 24% (£4,855.20), for £5,803.80 of CGT.
Buy-to-let sale on a £20,000 income
After £6,000 of costs the gain is £64,000 and the taxable gain £61,000. With £7,430 of taxable income, £30,270 of basic-rate band remains: that slice costs £5,448.60 at 18%, and the other £30,730 costs £7,375.20 at 24% — £12,823.80 due within 60 days.
Selling a business with BADR
A £400,000 qualifying gain less the £3,000 allowance leaves £397,000. Business Asset Disposal Relief taxes it at a flat 18% regardless of income, giving £71,460 of CGT.
Business sale above the £1 million BADR limit
The taxable gain is £1,500,000 − £3,000 = £1,497,000. The first £1 million gets BADR at 18% (£180,000). The £497,000 excess is taxed at the normal rates; an £80,000 income leaves no basic-rate band, so it all falls at 24% (£119,280), for £299,280 in total.
Frequently asked questions
What is the capital gains tax allowance for 2026/27?+
The annual exempt amount is £3,000 for individuals (and £1,500 for most trusts). It was cut from £12,300 in 2022/23 to £6,000 in 2023/24 and £3,000 from April 2024.
What are the UK CGT rates now?+
Since 30 October 2024 the main rates are 18% for gains within the basic-rate band and 24% above it, for both shares and residential property. Business Asset Disposal Relief and Investors’ Relief rose to 18% from 6 April 2026.
Do I pay CGT when I sell my home?+
Usually not. Private Residence Relief exempts the gain on your only or main home if it was your residence throughout ownership. Partial relief applies if you let it out or used part exclusively for business.
When do I have to pay capital gains tax?+
Gains on UK residential property must be reported and paid within 60 days of completion. Other gains are reported on a Self Assessment return and paid by 31 January after the end of the tax year.
Can I reduce capital gains tax legally?+
Common ways include using each year’s £3,000 allowance, transferring assets to a spouse to use their allowance and lower band, holding investments in an ISA or pension, and offsetting capital losses.
Are Scottish taxpayers charged different CGT rates?+
No. Capital gains tax uses UK-wide rates and bands, so Scottish taxpayers use the same 18% and 24% rates, based on the UK basic-rate band.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.