Capital Gains Tax Calculator UK 2026/27

Estimate mainstream individual Capital Gains Tax for 2026/27 using the £3,000 annual exempt amount.Taxable income after Personal AllowanceNet capital gain before annual exemption

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Result—

This Capital Gains Tax Calculator UK 2026/27 is tied to the 2026/27 tax year and models mainstream individual CGT. It is deliberately an annual planning view: £3,000 exemption plus 18% and 24% rates. A real payslip can still differ because payroll applies the employee’s tax code, pay frequency, cumulative history and any employer-specific deductions.

How to Use the Capital Gains Tax Calculator UK 2026/27

The taxable gain is considered alongside taxable income because unused basic-rate band can affect whether gains are charged at 18% or 24%. CGT uses the available basic-rate band after taxable income. That is why two people with the same gain can pay different amounts of 18% and 24% tax.

The calculator starts from a net gain after allowable costs and losses rather than sale proceeds. Special reliefs and complex disposals require separate advice or HMRC guidance.

2026/27 Personal Allowance

Before applying rates on this page, the model considers the 2026/27 standard Personal Allowance of £12,570 where relevant. High earners need the taper: the allowance shrinks above £100,000 adjusted net income and is fully removed by £125,140. That rule can alter £3,000 exemption plus 18% and 24% rates.

Income Tax Rates Used in the Model

Where this page needs the main UK non-savings rates, it uses the 2026/27 sequence of 20%, 40% and 45%. After allowances, the first £37,700 of taxable income sits in the basic band, with higher-rate income extending to £125,140 before the additional rate begins. For this calculator, the next step is not to apply every tax rule on the site. It is to connect the figure with Capital Gains Tax, using the £3,000 annual exemption and remaining basic-rate band. That narrower scope is intentional for individuals with a straightforward taxable disposal.

The calculation is intentionally narrow: £3,000 exemption plus 18% and 24% rates. Unrelated tax bands are not applied simply because they exist elsewhere in the UK system. An individual with a straightforward taxable gain can use this page to test how much basic-rate band remains for CGT purposes.

National Insurance and Other Deductions

Do not treat National Insurance as another Income Tax band. For pages involving employment cash pay, the model applies its own 2026/27 thresholds and the standard 8%/2% employee rates; for a page centred on mainstream individual CGT, NI appears only if it changes the question being answered. The reason it appears on Capital Gains Tax Calculator UK 2026/27 is page-specific: Capital Gains Tax can be misunderstood if the £3,000 annual exemption and remaining basic-rate band is left implicit. The wording here is aimed at individuals with a straightforward taxable disposal and the result should be read on that basis.

If a user adds education-loan deductions to Capital Gains Tax Calculator UK 2026/27, the plan must be identified first. From April 2026 the annual thresholds range from £25,000 on Plan 5 to £33,795 on Plan 4; Plan 1 is £26,900, Plan 2 £29,385 and postgraduate £21,000. Undergraduate-style plans use 9%, postgraduate 6%. BritTaxCalc treats this differently on Capital Gains Tax Calculator UK 2026/27 because the core output is Capital Gains Tax. By focusing on the £3,000 annual exemption and remaining basic-rate band, the page avoids suggesting that the same rule has identical importance on every calculator.

Who Should Use the Capital Gains Tax Calculator UK 2026/27

An individual with a straightforward taxable gain can use this page to test how much basic-rate band remains for CGT purposes.

The calculation centres on £3,000 exemption plus 18% and 24% rates. The net gain, taxable income and available basic band all matter; sale proceeds alone are not enough to calculate the tax. Keeping those drivers explicit makes it possible to rerun the same scenario after a pay rise, code change or new tax year without guessing which assumption moved.

Use the result to understand mainstream individual CGT, then move to a specialist page if another income source or deduction becomes material. A page that tries to solve salary, dividends, capital gains, benefits, pensions and multiple jobs in one default calculation would hide more assumptions than it explains.

Worked Examples for Capital Gains Tax Calculator UK 2026/27

Example 1: taxable income of £15,000 and a £8,000 net gain leave £5,000 after the £3,000 exemption; the mainstream CGT estimate is about £900.00.
Example 2: taxable income of £17,500 and a £11,000 net gain leave £8,000 after the £3,000 exemption; the mainstream CGT estimate is about £1,440.00.
Example 3: taxable income of £20,000 and a £14,000 net gain leave £11,000 after the £3,000 exemption; the mainstream CGT estimate is about £1,980.00.
Example 4: taxable income of £22,500 and a £17,000 net gain leave £14,000 after the £3,000 exemption; the mainstream CGT estimate is about £2,520.00.
Example 5: taxable income of £25,000 and a £20,000 net gain leave £17,000 after the £3,000 exemption; the mainstream CGT estimate is about £3,318.00.
Example 6: taxable income of £27,500 and a £23,000 net gain leave £20,000 after the £3,000 exemption; the mainstream CGT estimate is about £4,188.00.
Example 7: taxable income of £30,000 and a £26,000 net gain leave £23,000 after the £3,000 exemption; the mainstream CGT estimate is about £5,058.00.
Example 8: taxable income of £32,500 and a £29,000 net gain leave £26,000 after the £3,000 exemption; the mainstream CGT estimate is about £5,928.00.

Common Mistakes to Avoid

Using 2025/26 thresholds on a page labelled 2026/27.
Applying the highest marginal rate reached to the whole salary.
Forgetting the Personal Allowance taper above £100,000 where it applies.
Mixing Scottish employment-income rates with rest-of-UK bands.
Treating National Insurance or student loans as if they were part of Income Tax.
Assuming an annual estimate must equal every monthly PAYE deduction.