How Capital Gains Tax on property is worked out
- Work out the gain: the sale price, less the purchase price, buying and selling costs, and the cost of improvements.
- Take off reliefs: if the property was your main home at any point, Private Residence Relief covers that period plus the final 9 months of ownership.
- Take off the annual exempt amount: £3,000 per person for 2026/27, if you haven't used it on other gains.
- Apply the rate: 18% on the part of the gain that fits in your unused basic-rate band (up to £50,270 of income including the personal allowance), 24% on the rest.
Because the gain is added on top of your income, a large gain can be taxed mostly at 24% even if you're normally a basic-rate taxpayer. Selling in a tax year when your income is lower, or owning jointly with a spouse or civil partner, can reduce the bill.
What this calculator doesn't cover
- Lettings relief, which only applies if you shared the home with a tenant while living there.
- Other gains or losses in the same tax year, and losses carried forward from earlier years.
- Property owned through a limited company, which pays Corporation Tax instead.
- Non-UK residents, trusts, inherited property valued at probate, and Scottish income tax bands for working out unused basic-rate band.
Capital Gains Tax can be complicated. Speak to a qualified tax adviser or accountant before you sell.