If you sold shares, crypto, a second property, or another investment in the UK, this quick tool helps estimate how much Capital Gains Tax (CGT) you may owe. Enter your figures below to get an instant breakdown.
UK Capital Gains Tax Calculator
Estimate only. This tool does not include every relief or special rule. Check HMRC guidance or speak to a tax professional for formal advice.
How this UK capital gains tax calculator works
The calculator follows the standard individual CGT flow used in the UK:
- Start with your sale proceeds.
- Subtract allowable costs (purchase, buying/selling costs, and capital improvements).
- Offset eligible capital losses.
- Subtract your annual exempt amount.
- Apply CGT rates based on asset type and how much of your basic rate band is left.
Current rates used in this estimator
Residential property
- 18% on the part of the taxable gain within unused basic rate band.
- 24% on the part above that band.
Other chargeable assets
- 10% on the part of the taxable gain within unused basic rate band.
- 20% on the part above that band.
What counts as allowable costs?
Allowable costs can make a major difference to your tax bill. Common examples include:
- Legal fees for buying and selling.
- Stamp duty and other acquisition transaction costs.
- Estate agent and disposal fees.
- Capital improvements (for example, an extension), not normal repairs.
Example
Suppose you sell an investment asset for £150,000, bought it for £100,000, spent £3,000 on buying costs, £2,000 on selling costs, and £5,000 on improvements. You also have £2,000 of losses and a £3,000 annual exemption:
- Raw gain: £150,000 - (£100,000 + £3,000 + £2,000 + £5,000) = £40,000
- After losses: £40,000 - £2,000 = £38,000
- Taxable gain: £38,000 - £3,000 = £35,000
- Then the gain is split across lower/higher CGT rates depending on your taxable income.
Important limitations
This simplified calculator is designed for quick planning and does not account for every scenario. In particular, it does not model:
- Private Residence Relief details and partial relief calculations.
- Business Asset Disposal Relief and investor-specific reliefs.
- Complex share matching and pooling rules.
- Trusts, companies, non-resident rules, or temporary non-residence impacts.
Practical tips to reduce CGT legally
- Use your annual exempt amount each tax year where possible.
- Keep clear records of purchase documents and improvement invoices.
- Consider timing disposals across tax years.
- Review spouse/civil partner transfer options where appropriate.
- Get advice before large disposals or complex transactions.
Final note
Use this page as a planning tool for “capital gains tax calculator uk” estimates. For filing and compliance, always confirm figures against current HMRC rules and your personal circumstances.