How To Calculate Cgt

Calculate your potential capital gains tax liability with our accurate CGT calculator. Enter your details below to estimate your tax.

Comprehensive Guide: How to Calculate Capital Gains Tax (CGT) in the UK

Capital Gains Tax (CGT) is a tax on the profit you make when you sell (or ‘dispose of’) an asset that’s increased in value. It’s the gain you make that’s taxed, not the total amount you receive. Understanding how to calculate CGT correctly can help you plan your finances and potentially reduce your tax liability.

What is Capital Gains Tax?

Capital Gains Tax is applied to the profit (or gain) you make when you sell certain assets. These assets can include:

• Property that’s not your main home
• Shares that aren’t in an ISA or PEP
• Business assets
• Cryptocurrencies
• Personal possessions worth £6,000 or more (excluding your car)

You don’t usually pay tax when you sell your main home, give assets to your spouse or charity, or on certain types of investments like ISAs and premium bonds.

How to Calculate Your Capital Gain

The basic calculation for your capital gain is:

Sale proceeds – Purchase price – Allowable costs = Capital gain

Let’s break this down:

1. Sale proceeds: The amount you receive for the asset
2. Purchase price: What you originally paid for the asset
3. Allowable costs: These can include:
   • Fees for buying/selling the asset (e.g., estate agent fees, solicitor fees)
   • Costs of improving the asset (but not general maintenance)
   • Valuation fees to work out gains for tax purposes

Important Note on Timing

The date you acquired and disposed of the asset is crucial. For assets acquired before 31 March 1982, you may be able to use the market value at that date instead of the actual purchase price.

Capital Gains Tax Allowances and Reliefs

Before calculating your tax, you can deduct certain allowances and reliefs:

1. Annual Exempt Amount

Every individual has an annual tax-free allowance for capital gains (called the Annual Exempt Amount). For the 2024/25 tax year, this is:

• £3,000 for individuals
• £1,500 for trustees

This was reduced from £6,000 in 2023/24 and £12,300 in 2022/23, so planning disposals across tax years has become more important.

2. Private Residence Relief

If you’re selling your main home, you usually don’t pay CGT on any gain. However, there are exceptions:

• If part of your home is used exclusively for business
• If your garden or grounds (including buildings) are greater than 5,000 square metres
• If you’ve let out part or all of your home

3. Business Asset Disposal Relief (formerly Entrepreneurs’ Relief)

If you’re selling all or part of a business, you might qualify for this relief, which reduces the CGT rate to 10% on the first £1 million of qualifying gains over your lifetime.

4. Gift Hold-Over Relief

This allows you to defer paying CGT when you give away business assets or sell them for less than they’re worth to help the buyer.

Capital Gains Tax Rates 2024/25

The rate of CGT you pay depends on your income tax band and the type of asset:

Asset Type	Basic Rate Taxpayer	Higher/Additional Rate Taxpayer
Residential Property (not main home)	18%	28%
Other Chargeable Assets (shares, business assets, etc.)	10%	20%

Your taxable income is used to determine which rate applies. The basic rate band for 2024/25 is £12,571 to £50,270 (£43,662 in Scotland).

Step-by-Step Calculation Process

Here’s how to calculate your CGT liability:

1. Calculate your total gain: Sale price – purchase price – allowable costs
2. Apply any reliefs: Subtract Private Residence Relief, Business Asset Disposal Relief, etc.
3. Deduct your annual exempt amount: £3,000 for 2024/25
4. Add any unused losses: From previous years or the current year
5. Determine your taxable gain: This is the amount subject to CGT
6. Calculate the tax: Apply the appropriate rate based on your income and asset type

Example Calculation

Let’s work through an example for a higher-rate taxpayer selling a buy-to-let property:

• Purchase price: £200,000
• Sale price: £350,000
• Improvement costs: £20,000
• Selling costs: £5,000
• Annual exempt amount: £3,000
• No other reliefs apply

Calculation:

1. Total gain = £350,000 – (£200,000 + £20,000 + £5,000) = £125,000
2. Taxable gain = £125,000 – £3,000 = £122,000
3. CGT due = £122,000 × 28% = £34,160

Reporting and Paying Capital Gains Tax

How and when you report and pay CGT depends on the asset:

1. UK Residential Property

You must report and pay any CGT due within 60 days of completing the sale. This is done through HMRC’s Capital Gains Tax on UK property service.

2. Other Assets

For other assets, you report the gain in your Self Assessment tax return. The deadline is:

• 31 January following the end of the tax year for online returns
• 31 October following the end of the tax year for paper returns

Payment is due by 31 January following the end of the tax year.

Common Mistakes to Avoid

Many people make errors when calculating CGT that can lead to overpaying or underpaying tax:

• Forgetting to include all allowable costs: Make sure you include all eligible expenses in your calculation
• Incorrectly calculating the gain: Always use the correct dates and values
• Missing deadlines: Particularly important for property sales with the 60-day rule
• Not using losses: You can offset current year losses and bring forward unused losses from previous years
• Ignoring reliefs: Many people miss out on valuable reliefs they’re entitled to

Strategies to Reduce Your CGT Bill

There are several legitimate ways to reduce your capital gains tax:

1. Use your annual exempt amount: Time disposals to use your allowance each year
2. Transfer assets to your spouse: You can transfer assets between spouses tax-free, potentially using both annual exempt amounts
3. Offset losses: Sell loss-making investments to offset against gains
4. Use tax-efficient investments: Consider ISAs, pensions, or Enterprise Investment Schemes (EIS)
5. Defer gains: If possible, delay selling until a new tax year to use another annual exemption
6. Claim all available reliefs: Such as Business Asset Disposal Relief or Gift Hold-Over Relief

Capital Gains Tax for Different Asset Types

1. Property (Not Main Home)

Second homes, buy-to-let properties, and inherited properties are all subject to CGT when sold. The rate is 18% for basic rate taxpayers and 28% for higher rate taxpayers on the gain.

Special rules apply for:

• Properties that have been your main home at some point
• Properties you’ve let out (Let Property Relief may apply)
• Properties you’ve inherited

2. Shares and Investments

When you sell shares, units in a unit trust, or other investments, any gain is subject to CGT. The rates are 10% for basic rate taxpayers and 20% for higher rate taxpayers.

Special rules apply for:

• Shares received as gifts
• Employee share schemes
• Shares in unlisted companies (Business Asset Disposal Relief may apply)

3. Cryptocurrency

HMRC treats cryptocurrencies as assets for CGT purposes. You need to calculate the gain or loss each time you:

• Sell crypto for fiat currency
• Exchange one crypto for another
• Use crypto to pay for goods or services
• Give away crypto (except to your spouse)

The calculation can be complex due to the need to track the value of each transaction in GBP at the time it occurred.

4. Business Assets

When selling business assets, you may qualify for Business Asset Disposal Relief (formerly Entrepreneurs’ Relief), which reduces the CGT rate to 10% on qualifying gains up to a lifetime limit of £1 million.

Qualifying assets include:

• All or part of a business
• Assets used in a business you’re closing down
• Shares in a personal company

Capital Gains Tax for Non-UK Residents

If you’re non-UK resident, you may still need to pay CGT on:

• UK residential property (since April 2015)
• UK commercial property and indirect disposals (since April 2019)
• Other UK assets if you return to the UK within 5 years of leaving

Non-residents have the same annual exempt amount as UK residents and must report and pay CGT within 60 days for property disposals.

Recent Changes to Capital Gains Tax

The UK government has made several significant changes to CGT in recent years:

Change	Effective Date	Impact
Reduction in annual exempt amount from £12,300 to £6,000	April 2023	More people now pay CGT on smaller gains
Further reduction in annual exempt amount to £3,000	April 2024	Even more taxpayers affected by CGT
Extension of 60-day reporting/payment window for property	October 2021	Previously 30 days, now 60 days to report and pay
Inclusion of non-residents’ gains on all UK property	April 2019	Non-residents now pay CGT on commercial property too

These changes mean that careful planning is more important than ever to manage your CGT liability effectively.

When to Seek Professional Advice

While our calculator provides a good estimate, you should consider professional advice if:

• You have complex assets or multiple disposals
• You’re unsure about which reliefs apply
• You’re dealing with inherited assets
• You’re non-UK resident with UK assets
• You have significant gains that might push you into a higher tax band
• You’re considering tax planning strategies to reduce your liability

A qualified accountant or tax advisor can help you:

• Identify all available reliefs and exemptions
• Structure disposals to minimize tax
• Ensure you meet all reporting requirements
• Plan for future disposals

Useful Resources

For official guidance on Capital Gains Tax, consult these authoritative sources:

• GOV.UK: Capital Gains Tax Overview
• GOV.UK: CGT Rates and Allowances
• University of Oxford: Recent CGT Developments

Remember

This guide provides general information only. Tax laws are complex and subject to change. For specific advice about your personal circumstances, always consult a qualified tax professional.