Capital Gains Tax Calculator
Calculate UK Capital Gains Tax on shares using HMRC share matching rules. Import your trades or add them manually, then view your calculated gains by tax year.
Import your trades
Import trades from a CSV file or paste them from a spreadsheet. You can also skip this step and add trades manually in the next step.
About this CGT calculator
A free, private UK Capital Gains Tax calculator for shares and securities. Import your trades from CSV or Excel, and it applies HMRC's share matching rules (same-day, bed & breakfast (30-day), and the Section 104 pool) across every tax year from 2008/09 to 2026/27. Everything runs in your browser; no data leaves your device.
New to this? Read how to calculate CGT on shares or the current rates & allowances. See also the manual and worked examples.