Capital Gains Tax Calculator UK
Work out the tax on selling shares, property, or crypto — and the part most people miss: your gain is stacked on top of your income, so your salary decides whether you pay 18% or 24%.
Capital Gains Tax is charged on the profit when you sell or dispose of an asset, not the full sale price. Everyone gets a £3,000 annual exempt amount first; gains above it are taxed at 18% if you’re a basic-rate taxpayer or 24% if you’re higher-rate — and since the October 2024 changes, those same rates now apply to shares, crypto, and property alike. The catch most people miss is that the gain is the “top slice” of your income: it’s added on top of your salary, so it’s your income, not the size of the gain, that decides which rate you pay — a gain can even start at 18% and tip into 24% partway through. The £3,000 allowance is also use-it-or-lose-it and has been slashed from £12,300 just two years ago, which is why far more people now get caught. The good news: gains inside an ISA or pension are entirely CGT-free, transfers between spouses are tax-free and unlock a second allowance, and reported losses can cut future bills. This calculator shows what you’ll owe and what actually drives it. For investment wrappers, see ISA vs SIPP vs GIA; for dividends, the Dividend Tax Calculator.
Disposal and asset details
Losses and allowance
Income and rate band
Relief and reporting
Capital Gains Tax result
Estimated CGT due
Calculating…
Calculating…
Gain before losses
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Taxable gain
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Tax at lower rate
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Tax at higher rate
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Net proceeds after CGT
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Monthly set-aside
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Capital Gains Tax — quick lookup
The left table shows the tax on different gains for a basic-rate taxpayer versus a higher-rate one — same gain, different bills, because the rate follows your total income. The right lists the rates, allowance, and special reliefs you need. The headline is in the left table: it’s the income beneath your gain, not the gain itself, that sets your rate.
| Gain | Basic rate | Higher rate |
|---|---|---|
| £3,000 | £0 | £0 |
| £5,000 | £360 | £480 |
| £10,000 | £1,260 | £1,680 |
| £20,000 | £3,060 | £4,080 |
| £50,000 | £10,064 | £11,280 |
| Item | Figure |
|---|---|
| Annual exempt amount | £3,000 |
| Basic rate | 18% |
| Higher rate | 24% |
| Business Asset Disposal Relief | 18% |
| Property reporting | 60 days |
“Basic rate” assumes income around £30,000, so the gain stays in the basic-rate band (18%). “Higher rate” assumes income around £60,000, so the gain falls in the higher-rate band (24%). The first £3,000 is covered by the annual exempt amount in both cases. The £50,000 basic-rate figure is higher because part of that gain spills into the 24% band once it fills the remaining basic-rate space. Business Asset Disposal Relief gives a 18% rate on qualifying business gains, up to a £1m lifetime limit.
How Capital Gains Tax works
CGT trips people up because it isn’t a tax on what you sell something for — it’s a tax on the profit, and the rate depends on income that has nothing to do with the asset. Once you see how the gain stacks on top of your income, the two rates make sense.
You’re taxed on the gain, not the sale price
Capital Gains Tax applies to the gain — roughly, what you sold for minus what you paid, minus allowable costs like fees and improvements. You then subtract your £3,000 annual exempt amount, and what’s left is your taxable gain. CGT is only triggered when you actually dispose of an asset: selling it, giving it away, swapping it, or being compensated for its loss. Simply holding an asset that’s risen in value creates no tax until you sell.
The key idea: your gain is the “top slice”
This is the part most calculators skip. Your taxable gain is added on top of your taxable income to decide the rate. If your income plus gain stays within the basic-rate band, you pay 18%. If it pushes above the £50,270 higher-rate threshold, the part above is taxed at 24%. So the same £20,000 gain can be 18%, 24%, or a mix of both, purely depending on your salary. A single gain can even start at 18% and tip into 24% partway through, once it fills the remaining basic-rate space.
One rate for shares, crypto, and property
Until October 2024, shares and other assets enjoyed lower CGT rates than property. The Autumn 2024 Budget aligned them, so shares, crypto, funds, and second properties are now all taxed at 18% / 24%. Combined with the annual exempt amount falling from £12,300 to just £3,000, this means far more investors and second-home owners now face a CGT bill on disposals that would once have been tax-free. The allowance is also use-it-or-lose-it — you can’t carry an unused amount into next year.
Worked examples
Four scenarios showing how the same gain is taxed differently depending on your income, and how a wrapper changes everything.
Scenario 1 · Basic-rate investor, share gain
A gain taxed entirely at 18%
Less £3,000 allowance → £7,000 taxable, all within basic band
CGT: £7,000 × 18% = £1,260
An investor on £30,000 selling shares for a £10,000 gain deducts the £3,000 allowance, leaving £7,000. Their income leaves plenty of basic-rate band, so the whole gain is taxed at 18% — £1,260. This is the gentlest version: a basic-rate taxpayer with room to spare in the band. Spreading sales across tax years to use multiple £3,000 allowances could reduce even this.
Scenario 2 · Higher-rate investor, same gain
Same £10,000, taxed at 24%
Less £3,000 allowance → £7,000 taxable, all in higher band
CGT: £7,000 × 24% = £1,680
Take the exact same £10,000 gain but sit it on a £60,000 salary, and the whole taxable gain falls in the higher-rate band at 24% — £1,680, £420 more than the basic-rate investor. Identical asset, identical profit, more tax, purely because of the income underneath. This is the top-slice rule: your salary, not your gain, sets the rate.
Scenario 3 · A gain that crosses the threshold
Part at 18%, part at 24%
£17,000 taxable: £5,270 at 18% (£948.60) + £11,730 at 24% (£2,815.20)
CGT: £3,763.80
Here income of £45,000 leaves only £5,270 of basic-rate band before the £50,270 threshold. So the first £5,270 of the taxable gain is taxed at 18%, and the remaining £11,730 spills into the higher band at 24%, for £3,763.80. This split is why a single gain often isn’t a single rate — and why timing a sale for a lower-income year can genuinely cut the bill.
Scenario 4 · The same shares inside an ISA
The zero-tax route
CGT: £0 · no reporting to HMRC
Same gain outside an ISA (higher rate): £1,680
Gains on assets held inside an ISA or pension are completely CGT-free, with nothing to report. The £10,000 gain that costs a higher-rate investor £1,680 outside a wrapper costs nothing inside one. With the annual exempt amount down to £3,000, sheltering investments in ISAs — and gradually moving existing holdings in via “Bed and ISA” — is the most powerful long-term way to avoid CGT entirely.
What decides your CGT bill — and how to cut it
Most guides quote “18% or 24%” and stop. But how much you actually pay, and how much you can legally avoid, depends on four levers. Work through these before you sell:
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1
How much other income do you have?
Your gain stacks on top of your income, so your income decides whether you pay 18%, 24%, or a mix. A gain in a lower-income year — after retirement, a career break, or a lean year of self-employment — can be taxed far more cheaply. Timing matters as much as the gain itself.
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2
Are the assets inside a wrapper?
Gains inside an ISA or pension are entirely CGT-free and need no reporting. With the allowance at just £3,000, sheltering investments in an ISA is the single most effective move. Outside a wrapper, every gain above £3,000 is taxable; inside one, none of it is.
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3
Could you use a spouse’s allowance?
Transfers between spouses or civil partners are tax-free, on a “no gain, no loss” basis. Moving an asset to a partner before sale can use their £3,000 allowance and their lower tax band — potentially doubling the exempt amount and cutting the rate. It must be a genuine transfer of ownership.
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4
Have you used losses and the right relief?
Capital losses offset gains, and reported losses can be carried forward indefinitely — but only if you report them. Reliefs like Business Asset Disposal Relief (18% on qualifying business sales) or Private Residence Relief (your main home) can slash or remove the bill entirely.
£10,000 gain — same number, three situations
Identical gain, very different tax:
The same £10,000 gain costs anywhere from nothing to £1,680 depending only on where you hold the asset and what else you earn. That’s why “how much is Capital Gains Tax?” has no single answer — the rate is a property of your whole tax position, not the asset alone. For most investors the biggest win is using ISA allowances and spreading sales across tax years; for couples it’s a spouse’s allowance and band; for business owners it’s Business Asset Disposal Relief. The calculator works out which band your gain actually falls into for your figures.
Reporting: 60 days for property, Self Assessment for the rest
How you report depends on the asset. Gains on UK residential property must be reported and the tax paid within 60 days of completion, through a dedicated HMRC service — a tight deadline that catches second-home and buy-to-let sellers out. Gains on shares, crypto, and other assets are reported through your Self Assessment return by the following 31 January. Even a loss is worth reporting: you can only carry it forward to offset future gains if you’ve declared it to HMRC, generally within four years.
Two scenarios that change the picture
What if…
You split a gain with your spouse?
What if…
You moved investments into an ISA?
Key Capital Gains Tax terms explained
CGT brings together the annual exempt amount, the income-stacking rules, and the reliefs and wrappers that can reduce or remove it. The ten terms below cover what you’ll meet working out what you owe.
- Capital gain
- The profit on disposing of an asset — broadly, proceeds minus what you paid, minus allowable costs. CGT applies to this gain, not the full sale price, and only when you actually dispose of the asset.
- Annual exempt amount
- The £3,000 of gains you can realise tax-free each year, covering all assets combined. It’s use-it-or-lose-it — you can’t carry it forward — and has fallen sharply from £12,300 two years ago.
- Disposal
- The event that triggers CGT: selling, gifting, swapping, or being compensated for an asset. Simply holding an asset that has risen in value creates no tax until you dispose of it.
- CGT rates (18% / 24%)
- The two rates on taxable gains: 18% in the basic-rate band, 24% above it. Since October 2024 they apply to shares, crypto, and property alike, and which one you pay depends on your total income.
- Top slicing
- The rule that the taxable gain is stacked on top of your income to set the rate. Your income fills the bands first, so a single gain can be taxed partly at 18% and partly at 24%.
- Allowable costs
- Expenses you can deduct from the gain — purchase and sale fees, stamp duty, and the cost of improvements (but not maintenance). They reduce the taxable gain, so keeping records of them is worth real money.
- Capital loss
- A loss on disposing of an asset, which offsets gains and can be carried forward indefinitely — but only if reported to HMRC, generally within four years. An unreported loss is a wasted loss.
- Business Asset Disposal Relief
- A reduced 18% CGT rate on qualifying business gains, up to a £1 million lifetime limit, for sole traders, partners, and company directors selling their business. The rate rose from 14% in April 2026.
- Private Residence Relief
- Relief that exempts the gain on your main home for the period it was your only or main residence. It’s why most people never pay CGT when selling the house they live in.
- Bed and ISA
- Selling assets held outside a wrapper and rebuying them inside an ISA, so future gains are CGT-free. A common way to shelter a taxable portfolio over time, within the annual ISA limit.
Five mistakes people make with Capital Gains Tax
CGT catches people out because the rate depends on income and the deadlines vary by asset. These five errors, drawn from the recurring r/UKPersonalFinance and r/UKInvesting threads, are the costly ones.
Thinking the rate depends on the gain
The rate is set by your total income, not the size of the gain. The same £10,000 gain costs a basic-rate taxpayer £1,260 and a higher-rate one £1,680, and a large gain can straddle both rates. Add your income to your taxable gain before estimating the bill.
Cost: an underestimated bill, or a missed plan Fix: stack the gain on your income firstMissing the 60-day property deadline
Gains on UK residential property must be reported and paid within 60 days of completion, separately from Self Assessment. Second-home and buy-to-let sellers who assume they have until 31 January get caught by penalties. Diarise the 60-day window the moment a property sale completes.
Cost: late-filing penalties and interest Fix: report property gains within 60 daysNot reporting losses
Capital losses cut future gains, but only if declared to HMRC, generally within four years. Investors who sell at a loss and say nothing assume there’s no point — then can’t use that loss when a gain arrives later. Report losses even in a year with no tax to pay.
Cost: a wasted loss worth real tax later Fix: report losses to bank themWasting the annual exempt amount
The £3,000 allowance is use-it-or-lose-it — it can’t be carried forward. Selling a whole gain in one tax year uses just one allowance, when spreading the sale across two tax years would use two. Plan disposals around the 5 April year end to capture multiple allowances.
Cost: tax on gains a second allowance would cover Fix: spread sales across tax yearsForgetting a spouse’s allowance and band
Transfers between spouses are tax-free on a no-gain, no-loss basis, yet many run a whole gain through one person. Moving part of an asset to a lower-earning spouse before sale can use a second £3,000 allowance and a cheaper rate. The transfer must be a genuine change of ownership.
Cost: a wasted second allowance and lower band Fix: split assets before sellingFrequently asked questions
How much is Capital Gains Tax in the UK?
The first £3,000 of gains is tax-free under the annual exempt amount. Above that, you pay 18% if the gain falls in the basic-rate band and 24% if it falls in the higher-rate band. Since October 2024 these rates apply to shares, crypto, and property alike.
Which rate applies depends on your total income, not just the gain. For example, a £10,000 gain costs a basic-rate taxpayer £1,260 but a higher-rate taxpayer £1,680, because the gain is stacked on top of their income.
What is the Capital Gains Tax allowance?
The annual exempt amount is £3,000 of gains per year, free of CGT and covering all your assets combined. Only gains above it are taxable.
It’s use-it-or-lose-it: you can’t carry an unused amount into the next tax year. The allowance has been cut sharply, from £12,300 in 2022/23 to £6,000, then to £3,000, which is why far more people with modest portfolios or a second property now face a CGT bill.
Why is the same gain taxed differently for different people?
Because the taxable gain is the “top slice” of your income — it’s added on top of your salary and other income to decide the rate. Your income fills the tax bands first, and the gain is taxed at whatever band is left.
Someone on a £30,000 salary has plenty of basic-rate band left, so their gain is taxed at 18%. Someone on £60,000 has filled the basic-rate band, so their gain is taxed at 24%. A larger gain can even start at 18% and tip into 24% partway through.
Do I pay Capital Gains Tax on shares and crypto?
Yes, on the gain above your £3,000 allowance, at 18% or 24% depending on your income. Until October 2024 shares and crypto enjoyed lower rates than property, but the Autumn 2024 Budget aligned them, so all assets now share the same rates.
Gains on shares and crypto are reported through your Self Assessment return by the following 31 January. The big exception is anything held inside an ISA or pension, where gains are completely tax-free and need no reporting.
Are gains inside an ISA taxed?
No. Gains on assets held inside a Stocks and Shares ISA or a pension are completely CGT-free, and you don’t need to report them to HMRC at all.
This is the single biggest lever for investors. The £10,000 gain that costs a higher-rate investor £1,680 outside a wrapper costs nothing inside an ISA. With the annual exempt amount cut to £3,000, sheltering investments in ISAs — and moving existing holdings in via “Bed and ISA” — is the most effective long-term way to avoid CGT.
When do I have to report and pay CGT?
It depends on the asset. Gains on UK residential property must be reported and paid within 60 days of completion, through a dedicated HMRC online service. Gains on shares, crypto, and other assets are reported through your Self Assessment return by the following 31 January.
The 60-day property deadline catches many second-home and buy-to-let sellers out, so diarise it as soon as a sale completes. See the current routes at gov.uk.
Do I need to report a loss?
You should, even though you may not have to. Capital losses offset gains and can be carried forward indefinitely — but only if you’ve reported them to HMRC, generally within four years of the end of the tax year.
An unreported loss is a wasted loss: you can’t use it against a future gain if HMRC has no record of it. So even in a year with no tax to pay, reporting a loss banks it for later. This is especially valuable now the annual exempt amount is only £3,000.
How can I reduce my Capital Gains Tax?
The main legitimate levers are: use your £3,000 allowance every year and spread larger sales across tax years to use several; shelter investments in an ISA or pension, where gains are tax-free; transfer assets to a spouse before sale to use their allowance and band; and report losses to offset future gains.
Business owners may qualify for Business Asset Disposal Relief (18% on qualifying gains), and your main home is usually covered by Private Residence Relief. For larger disposals, an accountant can model the timing — see gov.uk.
Related calculators
Capital Gains Tax connects to the wrappers that avoid it, the other tax on investments, and the property gains that have their own rules. These calculators handle each piece.
Methodology & sources
How the maths works
The calculator starts from your gain — broadly your proceeds minus the cost and any allowable expenses — and deducts any losses and the £3,000 annual exempt amount to find the taxable gain. That taxable gain is then stacked on top of your taxable income (income above the £12,570 personal allowance). The part of the gain that fits within the remaining basic-rate band, up to the £50,270 higher-rate threshold, is taxed at 18%; anything above is taxed at 24%. This is why a single gain can be split between the two rates, and why the same gain costs more for someone with a higher income. Since the October 2024 changes, the 18% and 24% rates apply to shares, crypto, and property alike.
These are illustrative estimates to show how CGT behaves, not a personal tax computation. Real outcomes depend on your exact income and gains, allowable costs, available losses, whether assets sit inside an ISA or pension, any reliefs such as Private Residence Relief or Business Asset Disposal Relief, and the current rates and thresholds, all of which can change. Reporting deadlines differ by asset, with UK residential property requiring a 60-day return. The aim is to show which band your gain falls into and what drives the bill — not to replace tailored accountancy advice.
Assumptions and conventions used
- Annual exempt amount: £3,000 (use-it-or-lose-it)
- Basic-rate CGT: 18%
- Higher-rate CGT: 24%
- One rate set for shares, crypto, and property since Oct 2024
- Top slicing: gain stacked above taxable income
- Higher-rate threshold: £50,270 · personal allowance £12,570
- Business Asset Disposal Relief: 18%, £1m lifetime limit
- Property reporting: 60 days · other assets via Self Assessment
- ISA/pension gains are CGT-free · rates shown are illustrative current UK figures
Primary sources
Frequently asked questions
How much is Capital Gains Tax in the UK?
The first £3,000 of gains is tax-free under the annual exempt amount. Above that, you pay 18% if the gain falls in the basic-rate band and 24% if it falls in the higher-rate band. Since October 2024 these rates apply to shares, crypto, and property alike.
Which rate applies depends on your total income, not just the gain. For example, a £10,000 gain costs a basic-rate taxpayer £1,260 but a higher-rate taxpayer £1,680, because the gain is stacked on top of their income.
What is the Capital Gains Tax allowance?
The annual exempt amount is £3,000 of gains per year, free of CGT and covering all your assets combined. Only gains above it are taxable.
It’s use-it-or-lose-it: you can’t carry an unused amount into the next tax year. The allowance has been cut sharply, from £12,300 in 2022/23 to £6,000, then to £3,000, which is why far more people with modest portfolios or a second property now face a CGT bill.
Why is the same gain taxed differently for different people?
Because the taxable gain is the “top slice” of your income — it’s added on top of your salary and other income to decide the rate. Your income fills the tax bands first, and the gain is taxed at whatever band is left.
Someone on a £30,000 salary has plenty of basic-rate band left, so their gain is taxed at 18%. Someone on £60,000 has filled the basic-rate band, so their gain is taxed at 24%. A larger gain can even start at 18% and tip into 24% partway through.
Do I pay Capital Gains Tax on shares and crypto?
Yes, on the gain above your £3,000 allowance, at 18% or 24% depending on your income. Until October 2024 shares and crypto enjoyed lower rates than property, but the Autumn 2024 Budget aligned them, so all assets now share the same rates.
Gains on shares and crypto are reported through your Self Assessment return by the following 31 January. The big exception is anything held inside an ISA or pension, where gains are completely tax-free and need no reporting.
Are gains inside an ISA taxed?
No. Gains on assets held inside a Stocks and Shares ISA or a pension are completely CGT-free, and you don’t need to report them to HMRC at all.
This is the single biggest lever for investors. The £10,000 gain that costs a higher-rate investor £1,680 outside a wrapper costs nothing inside an ISA. With the annual exempt amount cut to £3,000, sheltering investments in ISAs — and moving existing holdings in via “Bed and ISA” — is the most effective long-term way to avoid CGT.
When do I have to report and pay CGT?
It depends on the asset. Gains on UK residential property must be reported and paid within 60 days of completion, through a dedicated HMRC online service. Gains on shares, crypto, and other assets are reported through your Self Assessment return by the following 31 January.
The 60-day property deadline catches many second-home and buy-to-let sellers out, so diarise it as soon as a sale completes. See the current routes at gov.uk.
Do I need to report a loss?
You should, even though you may not have to. Capital losses offset gains and can be carried forward indefinitely — but only if you’ve reported them to HMRC, generally within four years of the end of the tax year.
An unreported loss is a wasted loss: you can’t use it against a future gain if HMRC has no record of it. So even in a year with no tax to pay, reporting a loss banks it for later. This is especially valuable now the annual exempt amount is only £3,000.
How can I reduce my Capital Gains Tax?
The main legitimate levers are: use your £3,000 allowance every year and spread larger sales across tax years to use several; shelter investments in an ISA or pension, where gains are tax-free; transfer assets to a spouse before sale to use their allowance and band; and report losses to offset future gains.
Business owners may qualify for Business Asset Disposal Relief (18% on qualifying gains), and your main home is usually covered by Private Residence Relief. For larger disposals, an accountant can model the timing — see gov.uk.
Related calculators
Capital Gains Tax connects to the wrappers that avoid it, the other tax on investments, and the property gains that have their own rules. These calculators handle each piece.
Methodology & sources
How the maths works
The calculator starts from your gain — broadly your proceeds minus the cost and any allowable expenses — and deducts any losses and the £3,000 annual exempt amount to find the taxable gain. That taxable gain is then stacked on top of your taxable income (income above the £12,570 personal allowance). The part of the gain that fits within the remaining basic-rate band, up to the £50,270 higher-rate threshold, is taxed at 18%; anything above is taxed at 24%. This is why a single gain can be split between the two rates, and why the same gain costs more for someone with a higher income. Since the October 2024 changes, the 18% and 24% rates apply to shares, crypto, and property alike.
These are illustrative estimates to show how CGT behaves, not a personal tax computation. Real outcomes depend on your exact income and gains, allowable costs, available losses, whether assets sit inside an ISA or pension, any reliefs such as Private Residence Relief or Business Asset Disposal Relief, and the current rates and thresholds, all of which can change. Reporting deadlines differ by asset, with UK residential property requiring a 60-day return. The aim is to show which band your gain falls into and what drives the bill — not to replace tailored accountancy advice.
Assumptions and conventions used
- Annual exempt amount: £3,000 (use-it-or-lose-it)
- Basic-rate CGT: 18%
- Higher-rate CGT: 24%
- One rate set for shares, crypto, and property since Oct 2024
- Top slicing: gain stacked above taxable income
- Higher-rate threshold: £50,270 · personal allowance £12,570
- Business Asset Disposal Relief: 18%, £1m lifetime limit
- Property reporting: 60 days · other assets via Self Assessment
- ISA/pension gains are CGT-free · rates shown are illustrative current UK figures