Capital gains tax calculator
Tax on a gain, worked out properly: the gain stacks on top of your income, so part of it can fall at 18% and the rest at 24%.
How this is calculated
The gain is the sale proceeds less what you paid and less allowable costs. Allowable costs include buying and selling fees, stamp duty paid on purchase and capital improvements, but not repairs or maintenance.
Losses brought forward come off next, then the £3,000 annual exempt amount. Whatever is left is the taxable gain.
That taxable gain is then stacked on top of your income. The part that still fits inside the basic rate band is taxed at 18% and everything above at 24%, which is why two people with the same gain can pay very different tax.
Since 30 October 2024 the same rates apply to property, shares and crypto alike. There is no longer a separate higher rate for residential property.
Rates used · 2026/27
| Annual exempt amount | £3,000 per person |
| Basic rate | 18% |
| Higher and additional rate | 24% |
| Business Asset Disposal Relief | 18%, up to £1m lifetime |
| Property reporting | within 60 days of completion |
| Other assets | through Self Assessment |
Last checked July 2026. Source: HMRC and gov.uk.
Worked example
Selling a property for £320,000 that cost £240,000, with £12,000 of allowable costs, gives a £68,000 gain. After the £3,000 exempt amount, £65,000 is taxable. On a £40,000 income only £10,270 of basic rate band is left, so that slice is taxed at 18% and the remaining £54,730 at 24%. The bill is £14,984, an effective rate of 22%.
Common questions
Do I pay CGT on my own home?
Normally no. Private Residence Relief usually exempts the home you actually live in. It can be restricted if you let part of it out or the grounds are very large.
Why does my income affect the rate?
Because the gain is treated as the top slice of your income for the year. The part that fits in your remaining basic rate band is taxed at 18%, the rest at 24%.
Can my spouse help?
Transfers between spouses and civil partners are free of CGT, so moving an asset before selling can use both £3,000 allowances and both basic rate bands. Do it before the sale, not after.
When do I have to pay?
Residential property must be reported and paid within 60 days of completion. Other gains go through Self Assessment by the following 31 January. Missing the 60 day deadline is a common and avoidable penalty.