Capital Gains Tax Calculator UK
Calculate your CGT liability on shares, property and other assets for 2025/26 tax year
Calculate Your Capital Gains Tax
Your CGT Calculation
Enter your details on the left to calculate your Capital Gains Tax liability.
The calculator will show your total tax due, breakdown by rate bands, and explain what this means for your tax obligations.
Capital Gains Tax Rates 2025/26
Capital Gains Tax rates depend on your total taxable income and the type of asset you’re selling. The rates increased from April 2025 following the Autumn Budget.
| Asset Type | Basic Rate Taxpayers (18%) | Higher Rate Taxpayers (24%) |
|---|---|---|
| Shares & Securities | 18% | 24% |
| Residential Property | 18% | 24% |
| Other Assets | 18% | 24% |
How Capital Gains Tax Works
What is Capital Gains Tax?
Capital Gains Tax (CGT) is a tax on the profit you make when you sell or dispose of an asset that has increased in value. You pay CGT on the gain, not the total amount you receive.
CGT Calculation Process
The basic calculation follows these steps:
- Calculate your gain: Sale proceeds minus purchase price and allowable costs
- Deduct any losses from previous years
- Apply your annual allowance (£3,000 for 2025/26)
- Apply the appropriate tax rate based on your income and asset type
Allowable Costs
You can deduct certain costs when calculating your gain, including:
- Estate agent fees and solicitor costs when buying and selling
- Improvement costs that add value to the asset
- Professional valuation fees
- Stamp duty and other purchase taxes
Frequently Asked Questions
When do I need to pay Capital Gains Tax?
You must report and pay CGT through your Self Assessment tax return. For residential property, you must also report the gain within 60 days of completion and pay any tax due.
What assets are subject to CGT?
CGT applies to shares, investment properties (not your main home), business assets, valuable personal possessions worth over £6,000, and cryptocurrency. Your main residence is usually exempt.
Can I reduce my CGT bill?
Yes, you can use your annual allowance, offset losses from previous years, time disposals across tax years, transfer assets to your spouse, or consider holding investments in ISAs or pensions.
What happens if I don’t report capital gains?
HMRC can charge penalties and interest for late reporting. For residential property, penalties start from the day after the 60-day deadline. Always seek professional advice if unsure.
Planning Your Capital Gains
Tax Planning Strategies
Effective CGT planning can significantly reduce your tax liability. Consider spreading disposals across multiple tax years to use your annual allowance efficiently, or timing sales when your income is lower.
Record Keeping
Maintain detailed records of all purchases, sales, and improvement costs. HMRC requires evidence of your calculations, and good records will save time and potential disputes later.
References
HM Revenue & Customs. (2024). Capital Gains Tax: what you pay it on, rates and allowances. gov.uk.
HM Revenue & Customs. (2024). Tax when you sell property: Work out your gain. gov.uk.
HM Treasury. (2024). Autumn Budget 2024. gov.uk.
Institute of Chartered Accountants in England and Wales. (2025). Capital Gains Tax Technical Guidelines.
Association of Taxation Technicians. (2025). CGT Rate Changes and Planning Opportunities.