Capital Gains Tax Calculator
UK Capital Gains Tax on shares, property or a business sale using the annual exempt amount, your income tax band and the current rates.
- Free, no sign-up
- Runs in your browser, nothing is stored
- 2026/27 rates, reviewed 2nd September 2026
Capital Gains Tax Calculator
Enter your figures to see results.
How much Capital Gains Tax will I pay?
You pay Capital Gains Tax on the profit when you sell a second home, shares outside an ISA, a business or other valuable assets. The first £3,000 of gains each year is tax-free; above that the rate is 18% while the gain sits inside your unused basic-rate band and 24% beyond it. Selling a buy-to-let for a £53,500 gain on a £38,000 income costs about £11,384.
How to use this calculator
- Enter what you sold the asset for and what you paid for it.
- Add buying, selling and improvement costs, and any capital losses you have reported.
- Choose the asset type and enter your taxable income for the year, which decides how much of the gain is taxed at 18% rather than 24%.
What your result means
How to read the figure, what counts as normal, and what to do about it.
How UK Capital Gains Tax works
Capital Gains Tax is charged on the profit when you dispose of an asset that has increased in value: sell it, give it away, swap it or receive compensation for it. It applies to second homes and buy-to-lets, shares and funds outside an ISA or pension, business assets, land, and personal possessions worth over £6,000 (except cars). Your main home is normally exempt through Private Residence Relief.
The tax is not a flat percentage of the gain. Four things reduce or shape it: allowable costs of buying, selling and improving the asset; capital losses from other disposals; the annual exempt amount of £3,000; and your income tax band, which decides whether the gain is taxed at 18% or 24%.
Rates and allowances used
| Item | 2026/27 |
|---|---|
| Annual exempt amount (individuals) | £3,000 |
| Annual exempt amount (most trusts) | £1,500 |
| Rate within unused basic-rate band | 18% |
| Rate above the basic-rate band | 24% |
| Business Asset Disposal Relief rate | 18% (was 14% in 2025/26, 10% before) |
| BADR lifetime limit | £1,000,000 |
Reporting and paying
UK residential property: report the gain and pay the tax through HMRC's online property service within 60 days of completion. Miss it and there are automatic penalties even if no tax is due.
Everything else: report through Self Assessment by 31 January after the end of the tax year, or use HMRC's "real time" CGT service if you do not otherwise complete a return. You must report if total proceeds exceed £50,000 or the gain exceeds the annual exempt amount, even if no tax is payable.
Losses only reduce future gains if you report them to HMRC, normally within four years of the tax year they arose.
Legitimate ways to reduce the bill
- Transfer part of the asset to a spouse or civil partner before sale (no CGT on the transfer) so both annual exempt amounts and both basic-rate bands are used.
- Time disposals across two tax years to use two allowances.
- Realise losses in the same year to offset gains.
- Make pension contributions to extend your basic-rate band, moving more of the gain to 18%.
- Hold investments inside an ISA or pension, where gains are exempt.
- Check for reliefs: Private Residence Relief and lettings relief on a former home, BADR on a business, Investors' Relief, and rollover relief when replacing business assets.
Worked example: selling a buy-to-let
A landlord earning £38,000 sells a flat for £180,000. She bought it for £120,000; stamp duty, legal fees on purchase and sale, and agent's fees total £6,500. No losses.
Gain = 180,000 − 120,000 − 6,500 = £53,500. Less the £3,000 allowance: taxable gain £50,500.
Her taxable income is 38,000 − 12,570 = £25,430, leaving 37,700 − 25,430 = £12,270 of basic-rate band unused.
Tax = 12,270 × 18% + 38,230 × 24% = 2,208.60 + 9,175.20 = £11,383.80, an effective rate of 21.3% on the gain. It must be reported and paid within 60 days of completion. Had she owned the flat jointly with her spouse, two allowances and two basic-rate bands could have cut the bill substantially.
Frequently asked questions
Do I pay Capital Gains Tax when I sell my home?
Not usually. Private Residence Relief exempts a property that has been your only or main home throughout ownership. If you let it out or lived elsewhere for part of the time, a proportion of the gain may be taxable.
Is the £3,000 allowance per asset or per year?
Per person, per tax year, across all your gains. It cannot be carried forward if unused.
What costs can I deduct?
Costs of acquiring and disposing of the asset (stamp duty, legal fees, agent and broker fees, valuation fees) and capital improvements that add value (an extension, a new kitchen where none existed). Routine repairs, maintenance and mortgage interest are not allowable.
What is Business Asset Disposal Relief?
A reduced CGT rate (18% from April 2026) on gains from selling all or part of a trading business, or shares in your personal trading company, up to £1 million of gains over your lifetime. You must have owned the business or shares for at least two years and meet the 5% tests.
How do I pay CGT on a property sale?
Through HMRC's online "report and pay Capital Gains Tax on UK property" service within 60 days of completion. You will need a Government Gateway account. Any adjustment is then made through your Self Assessment return.
Are these rates current?
The tax year and review date appear under the calculator. CGT rates and the annual exempt amount are updated whenever HMRC changes them.
The maths behind this calculator
For anyone who wants to check the working or rebuild it in a spreadsheet.
The calculation
Gain = Proceeds − Purchase price − Allowable costs
Net gain = Gain − Capital losses
Taxable gain = Net gain − Annual exempt amount (£3,000)
Unused basic-rate band = £50,270 − Personal allowance − Taxable income
(capped at zero if income is already above £50,270)
Tax = min(Taxable gain, Unused band) × 18%
+ (Taxable gain − Unused band, if positive) × 24%
Business Asset Disposal Relief: Taxable gain × 18% (up to £1m lifetime) The gain is "stacked" on top of your income. Whatever room is left in your basic-rate band is taxed at 18%; anything above is taxed at 24%. From 30 October 2024 these rates have applied to all assets, so shares and property are now taxed alike.
Assumptions and limits
- You are a UK-resident individual with the standard personal allowance. Trusts, non-residents and companies are taxed differently.
- The annual exempt amount is fully available (not used against other gains in the same tax year).
- Private Residence Relief, lettings relief and other reliefs are not applied, so enter the gain after any relief you are entitled to.
- Business Asset Disposal Relief is applied to the whole gain when selected; check the qualifying conditions (two-year ownership, 5% shareholding and voting rights, employee or officer) and your remaining lifetime limit.
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