Calculate UK capital gains tax on investments, property, and other assets.
This calculator provides estimates for guidance only. It does not constitute financial advice. CGT rates and allowances may change. Always verify with HMRC or a qualified tax adviser.
Capital Gains Tax (CGT) is a UK tax on the profit you make when you sell or dispose of an asset that has increased in value. It applies to a wide range of assets including shares, investment properties, second homes, valuable personal possessions worth over GBP 6,000, and business assets. Your main home is usually exempt under Private Residence Relief. Since October 2024, CGT rates have been unified across all asset types. Previously, residential property attracted higher rates than shares and other assets, but the government simplified the system to a single set of rates: 18% for basic rate taxpayers and 24% for higher and additional rate taxpayers. The annual exempt amount has been reduced to GBP 3,000 for 2026-27, down from GBP 12,300 just a few years ago, meaning more disposals now attract a tax charge. Whether you are selling shares from an ISA transfer, a buy-to-let property, or business assets qualifying for Business Asset Disposal Relief (BADR), this calculator helps you estimate your CGT liability using the current 2026-27 rates.
To calculate your capital gains tax: 1. Enter your total capital gain. This is the profit from the disposal -- the sale price minus the purchase price, minus any allowable costs such as solicitor fees, stamp duty paid on purchase, and improvement costs. If you have multiple disposals in the same tax year, enter the combined total gain. 2. Enter your annual income. This is your total taxable income from employment, self-employment, pensions, and other sources. Your income determines how much of the basic rate band remains available for your capital gain, which affects whether you pay 18% or 24%. 3. Select whether Business Asset Disposal Relief applies. BADR is available on qualifying business disposals (selling a business, shares in a trading company where you are an employee with at least 5% shareholding, etc.). If eligible, the entire taxable gain is charged at the flat 18% rate regardless of your income. 4. Review your results. The calculator shows the total CGT due, your effective tax rate, how much of the annual exempt amount was used, and the split between gains taxed at the basic and higher rates.
CGT is calculated by first deducting the annual exempt amount (GBP 3,000) from your total gain. Only the remaining taxable gain is subject to CGT. For example, if you sell shares for a gain of GBP 20,000 and your annual income is GBP 30,000: - Taxable gain = GBP 20,000 - GBP 3,000 = GBP 17,000 - Your taxable income (GBP 30,000 - GBP 12,570 personal allowance) = GBP 17,430 - Remaining basic rate band = GBP 37,700 - GBP 17,430 = GBP 20,270 - Since GBP 17,000 fits entirely within the remaining basic rate band, all is taxed at 18% - CGT = GBP 17,000 x 18% = GBP 3,060 If your gain exceeds the remaining basic rate band, the excess is taxed at 24%. For higher rate taxpayers whose income already exceeds the basic rate band, the entire gain is taxed at 24%. Business Asset Disposal Relief simplifies this: the entire taxable gain (after the exempt amount) is taxed at a flat 18% rate, regardless of your income level. This relief has a lifetime limit of GBP 1 million.
CGT must be reported and paid via Self Assessment. For UK residential property disposals, you must report and pay within 60 days of completion using the HMRC online service. For other assets, CGT is reported on your annual tax return. Key reliefs that may reduce your CGT include: Private Residence Relief (your main home is usually exempt), letting relief, rollover relief for business assets, and gift hold-over relief. Transfers between spouses and civil partners are generally CGT-free, allowing couples to use both annual exempt amounts. Losses from other disposals in the same or previous tax years can be offset against gains. Allowable costs include purchase price, improvement costs (but not maintenance), and disposal costs such as estate agent and solicitor fees. The rates shown are for the 2026-27 tax year. The annual exempt amount has been frozen at GBP 3,000 and the basic rate band limit at GBP 37,700 for the foreseeable future.