Capital Gains Tax Calculator

If you hold accumulation units in offshore reporting funds (e.g. Vanguard UCITS ETFs like VWRL, VUSA, or iShares funds), the fund manager reports income that you must include in your tax return — even though no cash was distributed to you.

• Report date — the fund's reporting date (found on the fund factsheet or HMRC's reporting fund list). The calculator uses this to look up how many shares you held.
• ERI per share (£) — the excess reportable income per unit, from the fund manager's annual report. Often very small (e.g. £0.004231).
• Distribution date — the date the income is treated as distributed for tax purposes. Must be after the report date. This determines which tax year the adjustment falls into, and is the date used to add the ERI amount to your Section 104 pool cost basis.

The calculator multiplies your shares held on the report date by the per-share amount to compute the total ERI adjustment for each period. This increases your cost basis, reducing your capital gain when you eventually sell.

When a company performs a stock split (e.g. 10:1), your number of shares increases but the total value stays the same. Under TCGA 1992 s126–s131, this is not a disposal — the Section 104 pool cost is preserved and spread across the new shares.

• Split date — the effective date of the split or consolidation
• Shares held (before) — auto-calculated from your trade history on that date. This is your position just before the split took effect.
• New total (after) — the total shares you held after the split. For a 10:1 split of 50 shares, enter 500.

The calculator adjusts the pool: total cost stays the same, but shares and average price update. For example, 50 shares at £100 avg → 500 shares at £10 avg, same £5,000 total cost.

Enter any dividend income you received during the tax year. This includes cash dividends from UK and overseas shares and funds. These are not used in the CGT calculation — they are summarised in the report alongside any ERI amounts to give you a complete picture of investment income to declare on your tax return.

• Ticker — the stock or fund that paid the dividend (e.g. VWRL, AAPL).
• Amount (£) — the total dividend received in GBP (after any currency conversion).
• Date received — the date the dividend was paid to you. This determines which tax year it falls into.

The UK dividend allowance for 2024/25 is £500. Dividends above this are taxed at 8.75% (basic rate), 33.75% (higher rate), or 39.35% (additional rate).