Calculate capital gains

Estimate 2026/27 UK Capital Gains Tax for an individual in England or Northern Ireland after losses, reliefs, and the annual exemption.

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ToolCapital Gains Calculator
Input
Output
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How it works

Reliefs are deducted before the £3,000 Annual Exempt Amount, and taxable gain then fills any £37,700 basic-rate band not already used by taxable income. The portion inside that band is charged at 18% and the remainder at 24%; reliefs default to 0 because eligibility cannot be inferred.

Formula
taxable gain = max(0, gain − reliefs − £3,000)
tax = basic-band gain × 18% + remaining gain × 24%
  • The income field means taxable income after allowances, matching HMRC examples.
  • Rates are pinned to 6 April 2026 through 5 April 2027 and must be reviewed for a later disposal.

Worked example

A 20,000 gain, 40,000 other income
No further reliefs claimed
Input
											Gain: 20000
Annual income: 40000
Output
												Taxable gain: 17000
Amount at basic rate: 0
Amount at higher rate: 17000
Tax due: 4080
Annual exempt amount: 3000
Basic rate percent: 18
Higher rate percent: 24
Tax year: 2026/27

When to use this

Share disposals outside an ISA, residential-property gains without full Private Residence Relief, and year-end loss planning all use taxable gains after the Annual Exempt Amount.

Edge cases

  • Reliefs larger than the gain reduce net gain to 0 rather than creating a negative taxable gain.
  • Taxable income at or above £37,700 leaves no basic-rate band, so all taxable gain uses 24%.
  • The calculation does not cover trusts, carried interest, Business Asset Disposal Relief, Scotland-specific income bands, or gains outside 2026/27.

References