Capital Gains Tax calculator

What is Capital Gains Tax? 

Capital Gains Tax is a tax you pay on your profits. You declare anything you’ve earned from selling an asset (over a certain threshold) via a tax return. You’ll then need to file and pay your Capital Gains Tax bill by 31st January each tax year. 

The rate of CGT that you pay each year depends on the type of asset you’ve sold and how much you earn overall.

Use our Capital Gains Tax calculator to work out what tax you owe on your investment profits. Capital Gains Tax is basically a tax that you’re charged on money you make from selling an asset. When we say asset, this can mean any of the following that generate taxable gains:

• Property
• Jewellery
• Paintings
• Cryptocurrency
• Stocks and shares
• And more!

How is Capital Gains Tax calculated?

As you can see from using the calculator, you pay different rates depending on what you’re selling. Check out the basic Capital Gains Tax formula here 👇

When do I owe CGT?

After selling an asset, you only owe Capital Gains Tax on profits above £3,000 in the 2024/25 tax year. Anything less than that is tax-free. When you earn more than £3,000 during a tax year, this is taxable income which you will need to declare to HMRC and file a tax return. Make sure you do this by 31st January the tax year after you profit.

In practice, here are the deadlines to be aware of:

• You make £70,000 profit from selling a vintage car in June 2024
• This is the 2024/25 tax year
• Register for Self Assessment to declare the income by 5th October 2025
• Pay tax on your profit by 31st January 2026

2020 Capital Gains Tax changes 

If you sell a residential property, you now need to declare your profits within 30 days and pay any tax you owe. It’s via a digital service called the Real Time Capital Gains Tax Service. The 30 day rule has been in place since 6th April 2020. If you don’t do this, you could face a fine from HMRC. Be aware that this includes both UK residents and those who own UK property but live abroad. Take a look at the following exceptions to these changes:

• The legally binding contract for the sale was made before 6th April 2020
• You’re eligible for full private residence relief
• You sold the property to your spouse or civil partner
• The profit you made was within your tax free allowance 
• You sold the property for a loss
• The property is outside the UK

Read more about the CGT changes.

Do you owe CGT when you sell your home?

No. If you’re selling your main home, you don’t owe CGT. You only pay capital gains tax on property if you’re operating a buy-to-let business or have a second home that you’re selling. 

You also don’t need to worry about paying any CGT on your rental income. You’ll owe Income Tax on this and CGT at the point at which you sell up (if you’re not also living in the house). Read more about rental income tax via our guides.

How can I reduce the CGT I owe?

Reducing the CGT you owe may be tricky. There’s no tax credit or tax relief associated with it, however you can claim the Capital Gains Tax allowance to reduce your tax liability. Every tax year, you can earn up to £3,000 tax-free (previously £6,000) in profit. Anything less than this means you won’t have to file a tax return.