Capital Gains Tax applies to disposals of shares, crypto, second properties, and business assets above the £3,000 annual exempt amount. Rates are 18% in the basic-rate band and 24% above (aligned across asset types from 30 October 2024). This calculator stacks your gains correctly against your income to find the right rate.
£10,000 gain · No losses · £25,000 taxable income · Standard assets · AEA applied
£10,000 gain - £3,000 AEA = £7,000 taxable. £25k income leaves £12,700 of basic band remaining (£37,700 - £25k). All £7,000 fits in basic band: 7,000 × 18% = £1,260 CGT. Effective rate 12.6%. Take-home £8,740 (87% retention).
Share disposal — £20k gain, higher-rate taxpayer
£20,000 gain · No losses · £60,000 taxable income · Standard · AEA applied
£20k gain - £3k AEA = £17k taxable. £60k income already past the £37,700 basic-band ceiling — no basic-rate band remaining for CGT. All £17k taxed at higher rate: 17,000 × 24% = £4,080. Effective rate 20.4%. Higher earners pay 24% on every CGT pound above the AEA.
Second home sale — £50k gain, basic-rate taxpayer
£50,000 residential property gain · £30,000 income · AEA applied
£50k gain - £3k AEA = £47k taxable. £30k income leaves £7,700 of basic band. £7,700 × 18% = £1,386. Above basic band: £39,300 × 24% = £9,432. Total CGT £10,818. Note: residential property and standard asset rates have been the same since 30 October 2024 (£3,300 saving vs the old 28% higher rate).
Business sale with BAD relief — £100k gain
£100,000 business asset · BAD relief · £80,000 income · AEA applied
Business Asset Disposal Relief (formerly Entrepreneurs’ Relief) gives a flat 14% rate from 6 April 2025 (was 10% before, rises to 18% from April 2026). £100k - £3k AEA = £97k × 14% = £13,580. Same gain at standard rates would be £23,094 — BAD saves £9,514 on this disposal. Lifetime allowance £1m of qualifying gains.
Crypto gain offset by stock loss — £10k gain, £5k loss
£10,000 gain · £5,000 same-year loss · £25,000 income
Net gains: £10k - £5k loss = £5k. Less £3k AEA = £2k taxable. All in basic band: £2,000 × 18% = £360. Same-year losses offset gains pound-for-pound BEFORE the AEA — meaning small gains paired with losses can sometimes wipe out CGT entirely. Effective rate 7.2%.
Capital Gains Tax is one of the most-changed taxes in recent years. Three rate changes since 2023, AEA cut from £12,300 to £3,000, residential property aligned with standard rates in October 2024, BAD relief rising in steps. The calculator above uses 2025-26 rules — which apply to disposals made between 6 April 2025 and 5 April 2026.
Who pays CGT
Disposal of:
- Shares (outside ISAs and pensions) — basic rate 18% / higher rate 24%
- Cryptocurrency — same rates as shares; every swap is a disposal
- Second properties / buy-to-let — 18% / 24% (aligned with shares since Oct 2024)
- Business assets (sole-trader business, qualifying shares) — 14% with BAD relief (lifetime cap £1m)
- Valuables above £6,000 (jewellery, art, collectibles) — 18% / 24%
Doesn’t apply to:
- Your main home (Private Residence Relief)
- ISA gains (tax-sheltered)
- Pension fund gains (tax-sheltered)
- Gains under the £3,000 annual exempt amount
How rates work — the income-stacking trap
CGT rates depend on where the gain falls relative to your income tax basic-rate band:
Subtract from £37,700 to find basic-rate CGT band remaining
Gain fills basic band first at 18%
Excess gain at 24%
A £25k earner has £12,700 of basic CGT band available (£37,700 - £25,000) — small disposals stay at 18%.
A £60k earner has zero basic CGT band — every taxable gain pound is at 24%.
A £100k+ earner has the same problem PLUS personal allowance taper, but CGT itself isn’t tapered (different from income tax).
What this calculator doesn’t model
Private Residence Relief for main home
Lettings Relief for partial PRR cases
Non-UK-resident CGT on UK property
Multi-year planning (use multiple AEAs by spreading disposals)
Spousal transfers (transfer assets to spouse before disposal to use both AEAs)
EIS/SEIS deferral relief
Loss carry-forward tracking (you maintain this yourself)
BAD/Investors’ Relief lifetime cap tracking
For complex disposals (property with rental history, business sales, multi-year planning), professional advice is usually worth the £200-£500 fee — CGT mistakes can cost orders of magnitude more.
Tax year deadlines
Residential property: report and pay within 60 days of completion via the CGT on UK Property service.
Everything else: report on Self Assessment by 31 January following the tax year. Pay CGT alongside the rest of your SA bill.
Recent rate history (for context)
Period
Standard basic
Standard higher
Property basic
Property higher
AEA
2022-23
10%
20%
18%
28%
£12,300
2023-24
10%
20%
18%
28%
£6,000
6 Apr - 29 Oct 2024
10%
20%
18%
24%
£3,000
30 Oct 2024 onwards
18%
24%
18%
24%
£3,000
The 30 October 2024 change was a significant tax rise for shares and crypto — basic rate nearly doubled, higher rate up 4pp. Plan disposals knowing the new regime is permanent.
Common mistakes
Forgetting that the £3,000 AEA was £6,000 last year and £12,300 before that. The Annual Exempt Amount fell from £12,300 to £6,000 in April 2023 and again to £3,000 in April 2024. Any old advice quoting £12,300 is severely out of date. Plan disposals knowing only £3k is exempt per year.
Confusing ‘gain’ with ‘proceeds’. CGT is on the GAIN — sale price minus purchase price minus allowable costs (legal fees, improvement costs, broker fees). Not on total proceeds. £20,000 sold shares with £15,000 cost basis = £5,000 gain, not £20,000.
Not realising income tax band determines CGT rate. Many CGT calculators ignore your income — wrong. The CGT basic rate (18%) only applies to gain that fits in your remaining basic-rate income band (£12,570-£50,270). Excess gain is at 24%. Higher-rate taxpayers (£50k+ income) pay 24% on all gain above the AEA. The calculator handles this correctly.
Missing the same-year loss offset. Capital losses in the SAME tax year offset gains pound-for-pound BEFORE the AEA. Strategic loss-realisation in late March (the tax year ends 5 April) can substantially reduce CGT — sell underwater holdings before year-end to lock in losses against gains.
Forgetting losses can be carried forward. Unused capital losses (after current-year offset) can be carried forward indefinitely against future gains. You must REPORT them on a Self Assessment return within 4 years of the loss to claim them later. Many investors lose this relief by failing to report.
Treating crypto like overseas income. UK CGT applies to all crypto disposals by UK residents (selling, swapping, paying with crypto, gifting except to spouse). HMRC’s Crypto Compliance Bot (CryptoCompliance) cross-checks exchange data — non-disclosure is high-risk. Same rates as shares: 18% basic / 24% higher.
Forgetting reporting deadlines for property. Residential property gains must be reported and paid within 60 days of completion via the CGT on UK Property service. Standard CGT (shares, crypto) reports via Self Assessment by 31 January after the tax year. Different deadlines, different services.
What this calculator doesn't cover
Doesn’t model BAD/Investors’ Relief lifetime caps (£1m). Gains above the cap revert to standard rates.
Doesn’t model Private Residence Relief (your main home is exempt) or Lettings Relief (limited cases for properties with rental periods).
Doesn’t model non-resident CGT on UK property (different rules apply for non-UK-resident sellers).
Doesn’t include CGT-specific Stamp Duty Land Tax (SDLT) on property purchases.
Crypto-to-crypto swaps are CGT events — calculator treats this correctly but you need to track each swap’s gain individually.
Doesn’t track lifetime BAD relief usage across years — you need to track this yourself.
Single tax year only — multi-year tax planning (e.g. spreading disposals across years to use multiple AEAs) requires running the calculator separately for each year.
Assumes UK tax residency. Non-resident treatment is outside scope.
Frequently asked questions
What's the £3,000 annual exempt amount?
The first £3,000 of your net capital gains in any tax year is exempt from CGT — you pay nothing on this slice. It’s separate from the £12,570 income tax personal allowance and applies regardless of your income level. Was £6,000 in 2023-24 and £12,300 before that — fell sharply in recent years. Couples have separate AEAs (£6,000 combined), so transferring assets between spouses before disposal can effectively double the exemption.
What rate of CGT do I pay?
From 30 October 2024: 18% in the basic-rate band, 24% above. Aligned across asset types — same rates for shares, crypto, second homes, valuables. The basic-rate band is your unused income tax basic-rate allowance (£37,700 - your taxable income). Higher-rate taxpayers (£50k+ income) hit 24% from the first taxable pound of gain. Special rates: BAD relief 14%, Investors’ Relief 14%, Carried interest 32%.
Do I have to report capital gains under £3,000?
Only if you’re already in Self Assessment for other reasons OR your total disposals (proceeds, not gains) exceeded 4× the AEA (£12,000 in 2025-26). Below both thresholds and within the AEA, you don’t need to report. But if you sell £40,000 of shares at a £2,500 gain, you’re under the AEA but over the proceeds threshold — must report on SA even though no tax is due.
How do I report CGT?
Two routes. (1) Residential property: report and pay within 60 days of completion via the CGT on UK Property service at gov.uk. (2) Everything else (shares, crypto, business assets): report via Self Assessment by 31 January following the tax year. Crypto and shares are typically reported alongside other income; the SA software handles the maths.
Can I offset losses against gains?
Yes. Same-year capital losses offset capital gains pound-for-pound BEFORE the AEA. Unused losses can be carried forward indefinitely against future gains (must be reported on SA within 4 years of the loss to preserve them). Losses CAN’T usually offset income tax. Strategic late-March loss-realisation (selling underwater holdings before tax year end) is a common way to manage CGT.
What's Business Asset Disposal Relief?
BAD (formerly Entrepreneurs’ Relief) gives a reduced CGT rate on qualifying business disposals — selling a sole trader business, shares in your trading company, partnership share, etc. Currently 14% from 6 April 2025 (was 10% before, rises to 18% from 6 April 2026). Lifetime allowance £1 million of gains — beyond that, standard rates apply. Tight qualifying conditions: 5% shareholding, employee/director, 2-year holding period.
Does CGT apply to my main home?
Generally no — Private Residence Relief exempts most main-home sales. But: second homes, buy-to-lets, or properties used partly for business may attract CGT. Letting any portion of your main home for more than the rules permit can also crystallise a partial gain. PRR is its own complex topic; this calculator doesn’t model it. Property disposals usually need professional CGT advice.
What about crypto-to-crypto swaps?
Each swap is a CGT disposal of the asset you’re giving up. Selling Bitcoin for Ethereum: you’ve disposed of Bitcoin at its £-value at swap time; gain calculated against your Bitcoin cost basis. The Ethereum becomes a new holding with a cost basis equal to the Bitcoin’s £-value. Most active crypto users massively under-report this — every swap is an event.
Are CGT rates different in Scotland?
No — CGT is UK-wide. Scottish taxpayers use UK CGT rates and the UK basic-rate income band (£37,700) for the band-stacking calculation, even though their income tax bands differ. Scottish ‘higher-rate’ for income tax purposes (£43,663) doesn’t push you to higher-rate CGT until your taxable income exceeds £50,270.
About this calculator. Maintained by Jordan —
a UK seller and creator who actually uses these platforms (Etsy, eBay, Vinted, DistroKid).
Built to be accurate, mobile-fast, and honest about its limits. Spot a bug? Email
hello@payoutmath.co.uk.