Capital Gains Tax Calculator UK
Use our Capital Gains Tax Calculator UK to quickly estimate how much tax you’ll pay when you sell an asset. Whether it’s property, shares, or investments, this tool helps you calculate your capital gains and tax liability in seconds.
Simply enter your purchase price, selling price, and costs to get an accurate estimate — no complicated maths required.
What is Capital Gains Tax?
Capital Gains Tax (CGT) is a tax you pay on the profit (gain) when you sell or dispose of an asset that has increased in value.
It is managed by HMRC and applies to:
- Property (that’s not your main home)
- Shares and investments
- Business assets
- Valuable possessions
You only pay tax on the gain, not the total sale amount.
How to Use the Capital Gains Tax Calculator
Using this UK CGT Calculator is simple:
- Enter the purchase price of the asset
- Enter the selling price
- Add any allowable costs (fees, improvements, etc.)
- Instantly see:
- Your total gain
- Tax-free allowance applied
- Estimated Capital Gains Tax
How Capital Gains Tax is Calculated
1. Calculate Your Gain
Gain = Selling Price – Purchase Price – Costs
This is your taxable gain.
2. Apply the Annual Exempt Amount
You get a tax-free allowance (Annual Exempt Amount). Only gains above this are taxed.
3. Apply CGT Rates
Your CGT rate depends on your income and the type of asset:
For individuals:
- Basic rate taxpayers:
- 10% (most assets)
- 18% (residential property)
- Higher/additional rate taxpayers:
- 20% (most assets)
- 24% (residential property)
Example Calculation
Let’s say:
- Purchase price = £100,000
- Selling price = £150,000
- Costs = £5,000
Gain = £45,000
After applying your tax-free allowance, CGT is calculated on the remaining amount based on your tax band.
Our calculator does all of this instantly for you.
Who Should Use This Tool?
This Capital Gains Tax Calculator UK is ideal for:
- Property investors
- Landlords
- Shareholders and investors
- Business owners selling assets
- Anyone disposing of valuable assets
What Costs Can You Deduct?
You can reduce your gain by including:
- Purchase costs (legal fees, stamp duty)
- Improvement costs (not maintenance)
- Selling costs (agent fees, legal fees)
Including these can significantly lower your tax bill.
Common Mistakes to Avoid
- Forgetting to include allowable costs
- Not using the tax-free allowance
- Applying the wrong CGT rate
- Confusing profit with total sale value
A calculator helps ensure accuracy and better planning.
FAQs – Capital Gains Tax Calculator UK
How much is Capital Gains Tax in the UK?
It depends on your income and the asset type. Rates range from 10% to 24%.
Do I pay CGT on my main home?
Usually no, due to Private Residence Relief (with some exceptions).
What is the CGT allowance?
You get a tax-free allowance each year, and only gains above this are taxed.
When do I pay Capital Gains Tax?
You usually report and pay it through your Self Assessment with HMRC.
Is this calculator accurate?
It provides a reliable estimate, but your final tax may vary depending on your full financial situation.