UK Capital Gains Tax Calculator (2026/27)
Work out Capital Gains Tax on selling shares or funds in the 2026/27 tax year: your gain after costs and losses, the £3,000 tax-free allowance, and how your income splits the gain between 18% and 24%. Shares in an ISA are tax-free. Results update instantly, with every step shown. No sign-up.
Individual UK taxpayer selling shares or funds on or after 6 April 2026. Your taxable income is worked out as income minus the standard Personal Allowance (tapered over £100,000); other reliefs are not included.
- Gain on this sale£0
- Net gains this year (after losses)£0
- Tax-free allowance used£0
- Taxable gains£0
- Tax at 18%£0
- Tax at 24%£0
- Sale money kept after costs and tax£0
Quick answer
Selling for £30,000 what cost £15,100 (including costs), with income of £35,000, Capital Gains Tax for 2026/27 is about £2,142: £11,900 of taxable gains after the £3,000 allowance, £11,900 at 18% and £0 at 24%. Individuals, gains from 6 April 2026, England, Wales and Northern Ireland Income Tax bands. Rules from GOV.UK, checked 18 October 2026; they can change.
The same gains at different incomes
Your income decides how much of the £37,700 basic rate band is left for gains at 18%. Same sale and losses as above, held outside an ISA.
| Income | Taxable income | Gains at 18% | Gains at 24% | CGT |
|---|
Capital Gains Tax rates and allowance 2026/27
| 2026 to 2027 | |
|---|---|
| Tax-free allowance (Annual Exempt Amount) | £3,000 (£1,500 for trusts) |
| Gains within the basic rate band | 18% |
| Gains above the basic rate band, and higher or additional rate taxpayers | 24% |
| Basic rate band used for the test | £37,700 of taxable income |
GOV.UK's method for a basic rate taxpayer: work out your taxable income (income minus your Personal Allowance and any other Income Tax reliefs), work out your total taxable gains, deduct the tax-free allowance, and add what is left to your taxable income. The part within the basic Income Tax band is taxed at 18%; anything above it at 24%. GOV.UK also says you can use the allowance against the gains that would be charged at the highest rate.
The GOV.UK examples, reproduced
- Example 1: taxable income £20,000 and taxable gains of £12,600. After the £3,000 allowance, £9,600 is left. £20,000 + £9,600 = £29,600, less than £37,700, so it is all taxed at 18%: £1,728.
- Example 2: taxable income £20,000 and taxable gains of £52,600. After the allowance, £49,600 is left. £69,600 is more than £37,700, so 18% on £17,700 and 24% on £31,900: £10,842.
- Average cost of shares: buy 100 shares at 80p (£80) and later 300 at £1.20 (£360). 400 shares cost £440, an average of £1.10 each. Sell 150 and the cost for tax is £165.
These are checked by an automated test that runs before every update. If you bought the same shares at different times, enter the average cost of the shares you sold as "what you paid". If you bought the same shares again within 30 days of selling, special rules apply.
ISAs and other tax-free gains
GOV.UK: you pay Capital Gains Tax on “any shares that are not in an ISA or PEP”. You do not pay it on gains from ISAs or PEPs, UK government gilts and Premium Bonds, or on shares in employer Share Incentive Plans and Qualifying Corporate Bonds. Units in a unit trust and certain bonds held outside an ISA can be taxable.
Losses
- Losses are deducted from gains you made in the same tax year, in full.
- If your gains are still above the £3,000 allowance, you can deduct unused losses from earlier years, but only enough to bring them down to the allowance. The rest carries forward.
- You claim a loss on your tax return, up to 4 years after the end of the tax year you sold the asset.
Reporting and paying
You do not get a bill for Capital Gains Tax. If your taxable gains are above the allowance you need to report and pay. For gains other than UK residential property, that is usually through Self Assessment for the tax year after the sale, or if you're eligible, the “real time” Capital Gains Tax service by 31 December in the tax year after the sale. If you're registered for Self Assessment, you also need to report gains when the total you sold assets for was more than £50,000, even if no tax is due.
What this calculator does not cover
- Property, businesses (including Business Asset Disposal Relief), cryptoassets and personal possessions. GOV.UK has separate guidance for each.
- Trusts, personal representatives, companies and non-residents.
- Income Tax reliefs that reduce taxable income (for example pension contributions or Gift Aid), Scottish Income Tax bands, and the 30-day and same-day share matching rules.
- Gains made before 6 April 2026 (earlier tax years have different rates and allowances).
The formula
- Gain — sale price − purchase price − buying and selling costs
- Taxable gains — total gains − losses − £3,000 allowance
- Taxable income — income − Personal Allowance (£12,570, tapered over £100,000)
See the formula with your own numbers
These update live from the calculator inputs above.
Frequently asked questions
What is the Capital Gains Tax allowance for 2026/27?
GOV.UK: the Capital Gains tax-free allowance (the Annual Exempt Amount) is £3,000, or £1,500 for trusts. You only pay Capital Gains Tax on your overall gains above it.
What are the Capital Gains Tax rates on shares from 6 April 2026?
Higher and additional rate taxpayers pay 24% on gains. Basic rate taxpayers add their taxable gains (after the £3,000 allowance) to their taxable income: the part within the £37,700 basic rate band is taxed at 18% and anything above it at 24%.
Do I pay Capital Gains Tax on shares in an ISA?
No. GOV.UK lists gains from ISAs or PEPs among the gains you do not pay Capital Gains Tax on, and says you pay it on 'any shares that are not in an ISA or PEP'.
What is GOV.UK's Capital Gains Tax example?
Taxable income £20,000 and taxable gains of £52,600: take off the £3,000 allowance to leave £49,600. Added to income that makes £69,600, more than the £37,700 basic rate band, so you pay 18% on £17,700 and 24% on £31,900: £10,842.
Can I use losses to reduce Capital Gains Tax?
Yes. Losses are deducted from gains in the same tax year. If your gain is still above the allowance you can deduct unused losses from earlier years, but only enough to bring it down to the allowance; the rest carries forward. You claim losses on your tax return within 4 years of the end of the tax year.
Method & sources
- Calculation: gain = sale − cost − costs; same-year losses deducted in full, earlier losses only down to the allowance; £3,000 allowance; taxable income = income − Personal Allowance; gains within the remaining £37,700 basic rate band at 18%, the rest at 24%. ISA gains are not taxed.
- Rates from 6 April 2026, method and Examples 1 and 2: GOV.UK — gov.uk/capital-gains-tax/rates.
- Tax-free allowance £3,000: GOV.UK — gov.uk/capital-gains-tax/allowances.
- What you pay it on (ISAs, PEPs, gilts): GOV.UK — gov.uk/capital-gains-tax/what-you-pay-it-on. Totals, losses and the £50,000 reporting rule: work out if you need to pay, if you make a loss, reporting and paying.
- Shares: costs you can deduct and the average cost example: GOV.UK — gov.uk/tax-sell-shares, work out your gain, same company. Personal Allowance: gov.uk/income-tax-rates.
- All sources checked 18 October 2026. Verification: automated tests, run before every update, including the GOV.UK examples.
- Reviewed: .
Educational estimate only, not personal financial or tax advice. Share matching rules, reliefs and your full tax position can change the result. Rules can change and depend on your circumstances; confirm with GOV.UK, HMRC or a qualified adviser.
Run your own numbers
Enter your sale, costs and income to see how much Capital Gains Tax you'd owe.
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