UK Capital Gains Tax Calculator

What is Capital Gains Tax?

Capital Gains Tax (CGT) is a tax on the profit when you sell or dispose of an asset that has increased in value. You pay CGT on the gain, not the total amount received. Most assets are potentially liable, including shares, property (not your main home), and valuable personal possessions.

CGT Rates 2025-26 (Post October 2024 Budget)

The October 2024 Budget increased CGT rates and aligned them across asset types:

Annual Exempt Amount

The tax-free allowance has been significantly reduced:

• 2023-24: £6,000
• 2024-25 onwards: £3,000

Allowable Costs

You can deduct the following costs when calculating your gain:

• Purchase price (acquisition cost)
• Stamp Duty Land Tax paid on purchase
• Estate agent and solicitor fees
• Cost of improvements (not maintenance)
• Professional valuations for CGT purposes

Exemptions

• Principal Private Residence: Your main home is usually exempt
• ISAs: Gains within ISAs are tax-free
• Pensions: Gains within pension funds are exempt
• Gifts to spouse/civil partner: No CGT on transfers
• Gifts to charity: No CGT payable
• Personal possessions worth under £6,000

Losses

Capital losses can be offset against gains in the same tax year. Unused losses can be carried forward indefinitely to offset against future gains. You must report losses to HMRC within 4 years.

Reporting and Payment

• UK Residential Property: Report and pay within 60 days of completion
• Other Assets: Report on Self Assessment by 31 January
• Real Time CGT Service: Can use for property disposals

Business Asset Disposal Relief (BADR)

If you sell qualifying business assets, you may be eligible for a reduced rate of 10% (increasing to 14% from April 2025, then 18% from April 2026) on gains up to a£1,000,000 lifetime limit. This applies to shares in your own trading company and certain business assets.