Capital gains tax calculator

How this is worked out

In the UK the first ￡3,000 of gains a year is tax free. The rest is taxed at 18% where it falls in the basic rate band, the first ￡37,700 of taxable income, and at 24% above it. The gains sit on top of your other income after the ￡12,570 personal allowance, so the more of the band your income uses, the more of the gains pay 24%.

In the US long-term gains sit on top of your other income after the $16,100 standard deduction and pay 0% up to $49,450 of taxable income, 15% up to $545,500 and 20% above, plus the state's income tax and the 3.8% net investment income tax on income above $200,000. In Canada 50% of a capital gain is taxable: that part is added to your other income and taxed at the federal and provincial income tax rates.

Assumptions and limits

One person, under the 2026 rules (the 2026-27 tax year in the UK), with long-term gains (on assets held for more than a year) realised in one year and no losses carried from other years. Scottish taxpayers pay the UK rates on gains. In the US: a single filer, the standard deduction taken off the other income only, the state's top rate on the whole gain and no city or county tax. In Canada: the 2024 tax brackets with no basic personal amount. Reliefs, such as those on the sale of a business, and the alternative minimum tax are not included.