2025/26 tax year

UK Capital Gains Tax calculator for shares and funds

Calculates your 2025/26 Capital Gains Tax from your broker transaction history, using HMRC's same-day, 30-day and Section 104 matching rules.

  • All processing happens in your browser
  • Applies the same-day, 30-day and Section 104 rules
  • Produces SA108 figures, a full breakdown and a PDF

Supported brokers

T2Trading 212IBInteractive BrokersHLHargreaves LansdownFTFreetradeAJAJ BellVGVanguard UKSXSaxoeTeToro
  1. 1

    Add your CSV files

    Drop your CSV files here

    or click to browse

    Upload your transaction history from your broker. The more history you provide, the more accurate your Section 104 pool calculation will be.

    Exporting from your broker? Steps for each broker.

  2. 2

    Your total income

    £

    Total taxable income for 2025/26. Sets the split between the 18% and 24% rates.

    3

    Your name(optional)

Calculates your 2025/26 capital gains tax. Tax year ended 5 April 2026. Filing deadline 31 January 2027.

These figures are for informational purposes only and do not constitute tax advice. Always verify with a qualified accountant.