UK Capital Gains Tax Calculator 2026

Understanding Capital Gains Tax in the UK

Capital Gains Tax (CGT) is a tax on the profit you make when you sell an asset that has increased in value. It’s the gain you make, not the total amount of money you receive, that is taxed. This calculator helps individuals in the UK estimate their potential CGT liability for the 2026/27 tax year. Understanding CGT is crucial for anyone selling assets such as property, shares, or business assets, as it can significantly impact the net proceeds from a sale. Proper planning can help you manage your tax obligations effectively.

How Capital Gains Tax is Calculated

The calculation of Capital Gains Tax involves several steps, taking into account the type of asset, your total income, and available allowances.

The general steps are:

1. Calculate the Total Gain: This is the difference between the sale price and the purchase price, minus any allowable costs.
2. Deduct Allowable Costs: Costs of buying and selling (e.g., solicitor fees, estate agent fees, stamp duty, improvement costs) are deducted from the gain.
3. Apply the Annual Exempt Amount: For the 2026/27 tax year, the annual exempt amount is £3,000. This amount is deducted from your total gain to arrive at your taxable gain. If you have already used this allowance in the same tax year, you cannot apply it again.
4. Determine the Applicable Tax Rate: The rate of CGT you pay depends on two main factors:
   • Your total taxable income for the year: This includes all income excluding capital gains.
   • The type of asset sold: Residential property gains are taxed at different rates than gains from other assets (e.g., shares, business assets).

The CGT rates for the 2026/27 tax year are:

• Residential Property:
  • Basic rate taxpayers (income up to £50,270): 18%
  • Higher and additional rate taxpayers (income above £50,270): 28%
• Other Assets:
  • Basic rate taxpayers (income up to £50,270): 10%
  • Higher and additional rate taxpayers (income above £50,270): 20%

The portion of your taxable gain that falls within your unused basic rate income tax band will be taxed at the lower CGT rate, while any remaining taxable gain will be taxed at the higher rate.

Formula Breakdown

The calculation follows these steps:

1. Total Gain (TG) = Sale Price - Purchase Price - Costs of Buying and Selling - Other Allowable Costs
2. Taxable Gain (TxG) = TG - Annual Exempt Amount (if not already used)
3. CGT Liability (CGTL):
   • Determine the remaining basic rate income tax band: £50,270 - Your Total Taxable Income (excluding capital gains). If this value is negative, you are a higher rate taxpayer.
   • Apply the relevant CGT rates based on asset type and whether the gain falls within the basic or higher rate band.

*Note: The basic rate income tax band for 2026/27 is assumed to be £50,270 for illustrative purposes, based on current trends. Always refer to the latest HMRC guidance for exact figures.*

Key Variables Explained

• Type of Asset Sold: This distinguishes between residential property and other assets, as they are subject to different CGT rates.
• Sale Price: The total amount you received for the asset.
• Purchase Price: The original amount you paid for the asset.
• Costs of Buying and Selling: Expenses directly related to the acquisition and disposal of the asset, such as solicitor fees, estate agent fees, and Stamp Duty Land Tax (SDLT) on purchase.
• Other Allowable Costs: Further expenses that can reduce your gain, including costs of improving the asset (e.g., extensions, major renovations) or other incidental costs of disposal.
• Your Total Taxable Income (excluding capital gains): Your income from employment, self-employment, pensions, and other sources, after any personal allowances and deductions, but before considering any capital gains. This determines which CGT rates apply to your gain.
• Are you married or in a civil partnership?: While this calculator doesn’t directly factor in transfers between spouses, it’s an important consideration for overall tax planning as assets can be transferred between spouses without CGT liability.
• Have you used your Capital Gains Tax annual exempt amount for this tax year?: The annual exempt amount is a tax-free allowance for capital gains. For 2026/27, this is £3,000. If you’ve already used it on other gains, you cannot use it again.

Example Scenarios

Let’s look at a few examples to illustrate how Capital Gains Tax is calculated for the 2026/27 tax year.

Scenario	Asset Type	Sale Price	Purchase Price	Costs of Buying/Selling	Other Allowable Costs	Taxable Income	Used Annual Exemption	Total Gain	Taxable Gain	Estimated CGT
1. Residential Property - Basic Rate Taxpayer	Residential Property	£0	£0	£0	£0	£0	No	£0	£0	£0
2. Other Assets - Higher Rate Taxpayer	Other Assets	£0	£0	£0	£0	£0	No	£0	£0	£0
3. Residential Property - Higher Rate Taxpayer, Exemption Used	Residential Property	£0	£0	£0	£0	£0	Yes	£0	£0	£0

Official Sources and References

The information and calculations provided are based on guidance from HM Revenue & Customs (HMRC), the UK’s tax authority. For the most up-to-date and definitive information, always refer to the official government resources:

• HM Revenue & Customs (HMRC) Capital Gains Tax guidance: https://www.gov.uk/capital-gains-tax
• HMRC Income Tax rates and allowances: https://www.gov.uk/income-tax-rates

These sources provide comprehensive details on CGT rules, rates, allowances, and how to report your gains.

Important Tips and Considerations

• Record Keeping: Maintain meticulous records of all purchases, sales, and associated costs for any assets you own. This is crucial for accurately calculating your gain and proving allowable deductions to HMRC.
• Principal Private Residence (PPR) Relief: If you sell your main home, you may be eligible for PPR relief, which can significantly reduce or even eliminate your CGT liability. This calculator does not account for PPR relief, so if you are selling your main home, consult HMRC guidance or a tax advisor.
• Capital Losses: If you sell an asset for less than you bought it for (after accounting for costs), you make a capital loss. These losses can often be offset against capital gains in the same tax year or carried forward to future tax years.
• Spousal Transfers: Transfers of assets between spouses or civil partners are generally exempt from CGT. This can be a valuable planning tool for utilising both partners’ annual exempt amounts.
• Reporting Gains: You must report your capital gains to HMRC, typically through a Self Assessment tax return. For residential property sales, you usually need to report and pay CGT within 60 days of completion.
• Professional Advice: Tax laws can be complex and change frequently. For specific advice tailored to your personal circumstances, especially for large gains or complex situations, it is always recommended to consult a qualified tax advisor or financial planner.