UK Capital Gains Tax Calculator
Estimate ordinary individual CGT from a net gain after allowable losses. Special-rate gains and reliefs need a separate assessment.
Rule year: 2026/27 · GBP · Sources checked
Estimated Capital Gains Tax
Individual eligible for the full annual exempt amount, ordinary chargeable gains and unextended UK basic-rate band. Valid costs, losses and relief treatment already established. No Business Asset Disposal Relief, carried interest, trust rates, non-resident apportionment, ISA gains or residence-relief calculation.
For informational purposes only. This estimate is not financial advice, a tax return, a payroll calculation or a lender decision. See the supported circumstances and exclusions below.
How this calculator works
For the supported individual calculation, the annual exempt amount shelters up to £3,000 of established net gains. The remaining basic-rate Income Tax band can hold gains taxed at 18%; gains above that space use 24%. This page supports the ordinary rate calculation for common shares and residential gains, not special gains or relief elections. Enter net gains only after valid loss use has been established. A sale price is not itself a gain, and personal possessions or residence relief can change what is chargeable.
Formula and rules
Taxable gain = max(0, established net gain − £3,000). Basic-rate gain = min(taxable gain, max(0, £37,700 − taxable income)). CGT = 18% × basic-rate gain + 24% × remainder.
Assumptions and limitations
Individual eligible for the full annual exempt amount, ordinary chargeable gains and unextended UK basic-rate band. Valid costs, losses and relief treatment already established. No Business Asset Disposal Relief, carried interest, trust rates, non-resident apportionment, ISA gains or residence-relief calculation.
Worked example
£20,000 net gains less the £3,000 exemption leave £17,000. With £30,000 taxable income, £7,700 gains use 18% and £9,300 use 24%, giving £3,618 estimated CGT.
- Estimated Capital Gains Tax
- £3,618.00
- Gain after annual exempt amount
- £17,000.00
- Gain taxed at 18%
- £7,700.00
- Gain taxed at 24%
- £9,300.00
Official sources and review
Reviewed against the sources below on 2026-10-06. Rates are held in versioned rule modules. Versioned rules, official source review and year-specific calculation tests.
- GOV.UK: Capital Gains Tax rates ↗
£3,000 annual exempt amount and 18%/24% ordinary individual rates; special gains and reliefs excluded.
- GOV.UK: Income Tax rates and Personal Allowances ↗
2026/27 allowance £12,570, taper above £100,000, and income bands.
Common questions
Should I enter proceeds or profit?
Enter the established chargeable net gain after permitted costs and allowable loss treatment, not the sale proceeds.
Are gains inside an ISA included?
Qualifying ISA investment gains are generally outside this ordinary CGT calculation. Do not include exempt gains.
Does the tool calculate Business Asset Disposal Relief?
No. Special-rate gains, elections and relief eligibility are deliberately outside the ordinary-rate model.