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Capital Gains Tax Calculator
Estimate your CGT liability on shares, property, and other assets.
UK & US Rates
Both jurisdictions supported with current rates
Property & Assets
Different rates for residential property vs other assets
Annual Exemption
Tax-free allowance automatically applied
Calculate Capital Gains Tax
Enter your purchase and sale details to estimate CGT.
How Capital Gains Tax Is Calculated
Step-by-Step Process
1. Sale Price - Purchase Price = Gross Gain
2. Gross Gain - Allowable Costs = Total Gain
3. Total Gain - Annual Exemption = Taxable Gain
4. Taxable Gain × Tax Rate = CGT Owed
Allowable costs include buying and selling fees, legal costs, stamp duty, and improvement expenditure (but not maintenance).
Worked Example
You bought shares for £50,000 and sold for £80,000 with £1,000 in dealing costs. Total gain = £29,000. After the £3,000 annual exemption, taxable gain = £26,000. As a basic rate taxpayer at 10%, CGT = £2,600. Your effective rate on the total gain is just 9.0%.
Capital Gains Tax Rates 2025/26
Shares & Other Assets
Basic rate taxpayers pay 10% on gains. Higher and additional rate taxpayers pay 20%. In the US, long-term capital gains (assets held over 1 year) are taxed at 0%, 15%, or 20% depending on income. Short-term gains are taxed as ordinary income.
Residential Property
UK residential property gains attract higher rates: 18% for basic rate and 24% for higher/additional rate. Your main home is usually exempt under Private Residence Relief (PRR). The annual exempt amount of £3,000 still applies.
How to Use This CGT Calculator
Enter Prices
Purchase price, sale price, and any allowable costs.
Select Details
Choose jurisdiction, asset type, and your tax band.
View Breakdown
See your taxable gain, tax owed, and effective rate.
Legitimate Ways to Reduce Capital Gains Tax
- Use your annual exemption. The £3,000 allowance resets each tax year — use it or lose it. Consider timing disposals across tax years to use two allowances.
- Hold within an ISA or pension. Investments inside ISAs and pensions are completely exempt from CGT. Transfer existing holdings using Bed & ISA strategies.
- Transfer to your spouse. Transfers between spouses are CGT-free. Your spouse can then use their own annual exemption and potentially a lower tax rate.
- Offset capital losses. Realise losses to offset against gains in the same year. Unused losses carry forward indefinitely to reduce future tax bills.
Want deeper insights?
ARIA tracks your portfolio gains and losses with tax-lot accounting, helping you plan disposals and minimise CGT.
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