Calculator

Shares CGT Calculator 2026/27

Estimate CGT on shares or funds sold outside an ISA or pension. Enter your figures below — results update instantly.

Shares Capital Gains Tax

2026/27
£
£
£
£
£
£
Gross gain£0
Losses deducted£0
Annual exempt amount£0
Taxable gain£0
CGT at 18% (basic-rate band)£0
CGT at 24% (higher-rate band)£0
Total CGT estimate£0

This is a simplified estimate. Share matching rules and corporate actions are not modelled — see How it works below.

How it works

This calculator uses 2026/27 CGT rates for shares and funds:

  1. Gross gain = sale proceeds minus original purchase cost minus dealing costs.
  2. Deduct capital losses, then the annual exempt amount (£3,000).
  3. The taxable gain is split across the basic-rate and higher-rate bands using your income.
  4. 18% applies to gains within the basic-rate band; 24% to the remainder.

Share matching rules: HMRC uses a "same-day rule", "30-day rule" and "section 104 pool" to determine the cost base when shares are bought and sold at different times. This calculator assumes a single pool with the cost you enter — it is most accurate for a single purchase and single sale. Use a qualified tax adviser or HMRC's own tools for complex share portfolios.

Worked example

Sale proceeds £25,000 minus purchase cost £10,000 minus dealing costs £50 = gross gain of £14,950. After the £3,000 annual exempt amount, £11,950 is taxable. With income of £40,000, £10,270 of basic-rate band remains, so CGT is £1,849 at 18% and £413 at 24% — a total of approximately £2,262.

Note about ISAs

Shares, funds and investment trusts held inside a Stocks and Shares ISA are entirely free of CGT — dividends and capital gains are both sheltered. The ISA allowance is £20,000 per tax year. This calculator is for assets held outside an ISA or pension.

Official sources

Frequently asked questions

  • Are shares inside an ISA subject to CGT?

    No. Gains and income inside a Stocks and Shares ISA are completely free of CGT and income tax.

  • What are dealing costs?

    Broker commissions and stamp duty reserve tax (SDRT) paid on purchase are allowable costs. Platform fees and subscription costs are generally not deductible against CGT.

  • What if I bought shares at different times?

    HMRC uses share identification rules — same-day, 30-day and a section 104 pool — to calculate the allowable cost. This calculator does not model those rules; enter your best estimate of the average cost for a simple approximation.

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This calculator provides estimates for guidance only and does not constitute tax or financial advice. Tax rules can change and individual circumstances vary. Consult a qualified tax adviser before making decisions based on these figures.