Capital Gains Tax on shares
Paste in your share trades to see how much Capital Gains Tax is owed.
Capital Gains Tax calculator
You're looking at example trades. Import your own to see your tax.
01Your trades
02Your income
Salary, self-employed profit, rent, pensions, interest and dividends for the tax year. Use the pay figure on your P60, which already has salary sacrifice and any pension taken before tax removed.
Paid into a personal pension or Gift Aid?
Enter what you paid into pensions where your provider adds the tax relief, such as a SIPP, a personal pension or a workplace scheme like NEST, plus any Gift Aid. Leave out salary sacrifice and pension taken from your pay before tax.
The amount of gains everyone can make each year before paying Capital Gains Tax, set by the government. HMRC calls it the Annual Exempt Amount. It's £3,000 for 2026–27, so most people don't need to change it.
03Plan a sale (optional)
Try out sales you haven't made yet.
How HMRC matched your sales
Income does not change the gain or the £3,000 CGT tax-free allowance. It uses part of the basic-rate band, which can move gains into a higher CGT rate.
Buy cost includes purchase fees. Planned sales use the Section 104 pool; completed sales use the actual matched shares, which may include same-day or 30-day purchases. The £12,570 Personal Allowance goes down by £1 for every £2 of income over £100,000. The basic-rate band is £37,700 of taxable income, extended by personal pension and Gift Aid payments plus their basic-rate relief. Marriage Allowance and Blind Person's Allowance are not included. This estimates CGT for ordinary share gains; special reliefs and carried-forward losses are not included. Buying the same holding within 30 days after a planned sale may change its cost.
How it works
- 01Paste or import your trades. Import the CSV export from Trading 212, Freetrade, Hargreaves Lansdown, AJ Bell, Vanguard, Interactive Brokers, Revolut, Sharesight, Charles Schwab or Morgan Stanley, or any other CSV by choosing its columns. You can also paste rows with buy or sell, date, company, number of shares, price and fees.
- 02We match your sales. Each sale is matched to your purchases using HMRC's rules: same day first, then the next 30 days, then the average cost of the rest.
- 03We work out the tax. Your gains for the tax year are added up, the £3,000 allowance is taken off, and the rest is taxed at 18% or 24% depending on your income.
What this calculator covers. UK Capital Gains Tax on shares, ETFs, investment trusts and funds held in an ordinary investment account. It does not cover property, crypto, business assets or reliefs, share splits and mergers, or income reinvested inside accumulating funds, which can add to your cost.
Common questions
What is Capital Gains Tax?
Capital Gains Tax (CGT) is a tax on the profit you make when you sell something that has gone up in value. For shares, it is the difference between what you sold them for and what they cost you, including dealing fees.
How much profit can I make before I pay CGT?
Everyone gets a tax-free allowance each tax year (6 April to 5 April). For 2026–27 it is £3,000. You only pay tax on total gains above that. Losses you make in the same tax year are taken off your gains first.
What rate of CGT will I pay on shares?
18% or 24%. If your taxable income plus your gains fit inside the basic-rate income tax band, you pay 18%. Any part of your gains above that band is taxed at 24%. Higher and additional-rate taxpayers pay 24% on all of it.
Why does my income affect my CGT?
Your income does not change the size of your gain. It uses up part of the basic-rate band first, which decides how much of your gain is taxed at 18% and how much at 24%.
What happens if I sell shares and buy them back within 30 days?
HMRC treats the sale as matched with the shares you bought back, not with your older shares. This is sometimes called the bed and breakfast rule. It stops people selling and quickly rebuying just to use their allowance. The calculator applies this rule to the trades you paste in.
Do I pay CGT on shares in an ISA or pension?
No. Shares held in an ISA or a pension such as a SIPP are free of Capital Gains Tax. Only enter trades from ordinary (taxable) investment accounts. Gifts to your husband, wife, civil partner or a charity are also usually tax-free.
When do I need to tell HMRC?
If you owe CGT, you can report it using HMRC's online Capital Gains Tax service by 31 December after the tax year ends, or on a Self Assessment tax return. Payment is due by 31 January. If you are in Self Assessment and sold more than £50,000 of assets in the year, you must report the sales even if no tax is due.