2026/27 Tax Year

Capital Gains Tax on Shares Calculator

Use this when you have sold shares or funds outside an ISA and want a clean first-pass estimate of the Capital Gains Tax bill for 2026/27, split across the 18% and 24% bands.

Scope note: this page is built for a standard share disposal using pooled cost, costs of purchase and sale, carried losses, and 2026/27 individual rates. Same-day and 30-day matching rules can override the simple pooled-cost method.

Your disposal

Use the pooled or matched cost for the shares disposed of, not the total cost of your whole account.
This should already be after Personal Allowance and any income-tax reliefs.
Estimated Capital Gains Tax due on this share disposal
£0 Estimated disposal cash after sale costs and CGT: £0
Gross gain before losses and allowance£0
Taxable gain after losses and annual exempt amount£0
Gain taxed at 18%£0
Gain taxed at 24%£0
Annual exempt amount used£0
Basic-rate band left before the gain£0
Net cash after CGT£0

What this means

The rate on share gains now depends on how much of the basic-rate band is still unused once your taxable income has taken its slice. The annual exempt amount should normally be used against the highest-taxed gains first.

My scenarios

What this page assumes

This calculator is for a standard listed-share or fund disposal where you already know the allowable cost of the shares sold. It is deliberately simpler than a full HMRC share matching engine.

Sources and assumptions

GOV.UK tax when you sell shares GOV.UK work out your gain on shares GOV.UK same company share-pooling guidance GOV.UK Capital Gains Tax rates GOV.UK Capital Gains Tax allowances

This page uses the 2026/27 annual exempt amount of £3,000 and the post-6 April 2026 individual rates of 18% and 24%.