CGT on shares & funds
Estimate the Capital Gains Tax on selling shares, funds or ETFs outside an ISA. It takes the £3,000 allowance off the gain, then splits the rest across the 18% and 24% rates using your income.
30-day rule: selling and buying the same shares back within 30 days matches the sale to the repurchase, so it does not realise the gain you expected.
How CGT on shares is worked out
The gain is your sale proceeds minus the cost of the shares sold minus dealing costs. For shares of the same class this uses the pooled, or Section 104, cost: all your buys are averaged into one cost per share. The first £3,000 of your total gains for the year is covered by the annual exempt amount and is tax-free.
The taxable gain then stacks on your income to set the rate. The part that fits inside your unused basic-rate band is taxed at 18%, and anything above at 24%. These rates rose from 10% and 20% on 30 October 2024, so shares and funds now carry the same rates as second properties. Gains inside an ISA or pension stay exempt, so this only applies to a general investment account.
Worked example
Sell fund units for £30,000 that cost £15,000, with £150 of dealing fees, and the gain is £14,850. After the £3,000 allowance, £11,850 is taxable. On a £45,000 income, £5,270 fits the basic band at 18% and £6,580 sits above at 24%, a bill of £2,528. Buying the same fund back within 30 days would match the sale and undo it.
Common questions
What are the CGT rates on shares in 2026/27?
Gains above the £3,000 allowance are taxed at 18% within your basic-rate band and 24% above it. These rates rose from 10% and 20% on 30 October 2024, so shares now match property.
How much can I gain before paying CGT?
The annual exempt amount is £3,000 for 2026/27. Total gains up to that across all your shares and funds in the year are tax-free. Only the excess is taxed.
What is the 30-day bed-and-breakfast rule?
If you sell shares and buy the same shares back within 30 days, the sale is matched against that repurchase, not your older holding. This blocks selling just to use your allowance and buying straight back. Wait more than 30 days, or buy back inside an ISA or a spouse buys instead, to sidestep the match.
Do I pay CGT on shares held in an ISA or pension?
No. Gains inside a Stocks and Shares ISA or a pension are free of Capital Gains Tax. This calculator is for holdings in a general investment account, outside those wrappers.
How is the gain worked out if I bought in tranches?
Shares of the same class in the same company are pooled into a Section 104 holding at their average cost. Your gain is the sale proceeds minus the average cost of the shares sold, after the same-day and 30-day matching rules are applied first.