Capital Gains Tax Calculator UK

Calculate your Capital Gains Tax based on UK 2024/25 tax rates.

Math Audited
Asset Type
Capital Gain (Profit)£0.00
£
£0.00£200,000.00
Total Taxable Income£30,000.00
£
£0.00£200,000.00
Total Tax
£0.00
Total Gain£0.00
Annual Exempt Amount (AEA)-£3,000.00
Taxable Gain£0.00
BandPortion of GainTax RateTax Due
Exempt (AEA)£0.000%£0.00

About the UK Capital Gains Tax Calculator

Capital Gains Tax (CGT) in the United Kingdom is a tax levied on the profit you make when you sell or dispose of an asset that has increased in value. It is one of the most widely misunderstood aspects of the tax system, primarily because people often mistakenly assume they will be taxed on the total amount they receive from a sale. In reality, CGT applies strictly to the gain—the difference between what you paid for the asset and what you sold it for, minus certain allowable deductions. Whether you are selling shares, a second home, a buy-to-let property, or other chargeable assets, understanding your potential CGT liability is crucial for effective financial planning. The calculation process involves several variables, including your total taxable income, the type of asset being disposed of, and the available Annual Exempt Amount (AEA). For the 2024/25 tax year, the AEA is set at £3,000, meaning the first £3,000 of your total gains across all assets are entirely tax-free. However, gains exceeding this threshold are subject to taxation at rates that depend both on your Income Tax band and whether the asset is residential property or something else like shares. Because the UK tax system uses a progressive banding structure, a large capital gain can push your total income into a higher tax bracket, resulting in a split-band calculation where part of your gain is taxed at the basic rate and the rest at the higher rate. This calculator provides a precise, step-by-step breakdown of these mechanics, enabling you to estimate your liability with confidence based on the latest HMRC rules.

Mathematical Formula & Logic

The mathematical process for calculating UK Capital Gains Tax is highly structured and sequential, involving the deduction of allowances and the application of income-dependent tax bands. Step 1: Calculate the Total Gain Total Gain = Sale Price − Purchase Price − Allowable Costs Allowable costs may include fees paid for professional advice, stamp duty, or capital improvements made to a property. Step 2: Calculate the Taxable Gain Taxable Gain = Total Gain − Annual Exempt Amount (AEA) If your total gain is less than or equal to the AEA, your taxable gain is zero and no tax is due. For the 2024/25 tax year, the AEA is fixed at £3,000 for individuals. Step 3: Determine the Unused Basic Rate Band To find out what rate applies, you must determine how much of your basic rate income band remains available. The basic rate band limit is generally £50,270. Unused Basic Rate Band = £50,270 − Your Taxable Income If your taxable income already exceeds £50,270, your unused basic rate band is zero, and you are classified as a higher rate taxpayer. Step 4: Apply the Appropriate Tax Rates The tax rates depend entirely on the asset type and the available basic rate band: For Standard Assets (e.g., Shares, Funds, Crypto): - Basic Rate (within the unused basic rate band): 10% - Higher Rate (above the basic rate band): 20% For Residential Property (e.g., Second Homes, Buy-to-Lets): - Basic Rate (within the unused basic rate band): 18% - Higher Rate (above the basic rate band): 24% Step 5: The Split-Band Calculation If your taxable gain is larger than your unused basic rate band, the gain is split. The portion of the gain that fits into the unused basic rate band is taxed at the lower rate (10% or 18%), and the remaining portion of the gain is taxed at the higher rate (20% or 24%). Total CGT = (Portion in Basic Band × Basic Rate) + (Portion in Higher Band × Higher Rate) This tiered approach ensures that capital gains are treated as top-slice income, sitting on top of your regular earnings to determine the final tax obligation.

Step-by-Step Example

Let us examine two detailed scenarios to illustrate the difference between basic rate, higher rate, and split-band calculations, as well as the differential treatment of shares versus property. Scenario A: Selling Shares (Split-Band Calculation) Suppose you sell shares resulting in a total gain of £33,000. Your regular taxable income is £30,270. 1. Deduct the Annual Exempt Amount (AEA): Taxable Gain = £33,000 − £3,000 = £30,000. 2. Calculate the unused basic rate band: Unused Band = £50,270 (limit) − £30,270 (income) = £20,000. 3. Split the taxable gain across the bands: Your £30,000 taxable gain exceeds your £20,000 unused basic rate band. Therefore, the first £20,000 falls in the basic rate band, and the remaining £10,000 falls in the higher rate band. 4. Apply the rates for shares (10% basic, 20% higher): Tax at basic rate = £20,000 × 10% = £2,000. Tax at higher rate = £10,000 × 20% = £2,000. 5. Total Capital Gains Tax = £2,000 + £2,000 = £4,000. Scenario B: Selling Residential Property (Higher Rate Calculation) Suppose you sell a buy-to-let property with a total gain of £53,000. Your regular taxable income is £12,570 (meaning you only earn up to the personal allowance, but for this calculation, let us assume your taxable income after the personal allowance is £12,570). 1. Deduct the Annual Exempt Amount (AEA): Taxable Gain = £53,000 − £3,000 = £50,000. 2. Calculate the unused basic rate band: Unused Band = £50,270 (limit) − £12,570 (income) = £37,700. 3. Split the taxable gain across the bands: The first £37,700 of the £50,000 gain falls in the basic rate band. The remaining £12,300 falls in the higher rate band. 4. Apply the rates for residential property (18% basic, 24% higher): Tax at basic rate = £37,700 × 18% = £6,786. Tax at higher rate = £12,300 × 24% = £2,952. 5. Total Capital Gains Tax = £6,786 + £2,952 = £9,738. These examples demonstrate how the progressive nature of the UK tax system requires careful separation of the gain across different tax bands to arrive at the correct liability.

Reference Data & Values

assetrateaeanotes
Shares (Basic Rate)10%£3,000Applies within remaining basic rate band
Shares (Higher Rate)20%£3,000Applies above basic rate band
Property (Basic Rate)18%£3,000Applies within remaining basic rate band
Property (Higher Rate)24%£3,000Applies above basic rate band

Frequently Asked Questions

Capital Gains Tax (CGT) is a tax levied on the profit you make when you sell, gift, or otherwise dispose of an asset that has increased in value. Importantly, it is the gain you make that is taxed, not the total amount of money you receive from the transaction. It applies to a wide range of chargeable assets, including most personal possessions worth £6,000 or more, property that is not your main home, shares that are not held in an ISA, and business assets.
The Annual Exempt Amount is a tax-free allowance that every individual in the UK is entitled to. It represents the total amount of capital gains you can make in a single tax year before any Capital Gains Tax becomes due. For the 2024 to 2025 tax year, the government has set the Annual Exempt Amount at £3,000. This is a significant reduction from previous years, meaning more individuals are likely to be subject to CGT on smaller gains.
Your CGT rate is intimately linked to your Income Tax band. Capital gains are treated as the top slice of your income. To determine your rate, you must add your taxable capital gain to your total taxable income. If this combined amount is within the basic rate band (up to £50,270), your gains are taxed at the basic rate. If the combined amount pushes into the higher rate band, the portion of the gain that exceeds the basic rate threshold is taxed at the higher rate.
Yes, this is one of the most frequent misunderstandings regarding Capital Gains Tax. Many people fear they will be taxed on the entire gross proceeds of a sale. In reality, CGT only applies to the net profit. You calculate this by subtracting the original purchase price of the asset, along with any allowable incidental costs (such as solicitor fees, stamp duty, or capital improvements), from the final sale price.
No, if your total capital gains across all asset disposals in the tax year are below the Annual Exempt Amount of £3,000, your tax liability is zero. Furthermore, you generally do not need to report these gains to HMRC unless you are already registered for Self Assessment and either the total amount you sold the assets for was more than four times your allowance, or you need to claim a capital loss.
The UK government implements different tax rates depending on the asset class, often to shape investment behavior or generate specific tax revenues. Gains from residential property (which typically excludes your primary residence due to Private Residence Relief) are taxed at higher rates—18% for basic rate taxpayers and 24% for higher rate taxpayers. In contrast, regular assets like shares or cryptocurrency are taxed at lower rates of 10% and 20% respectively. This policy choice makes property investment relatively more heavily taxed on disposal.
The UK tax system handles this through a split-band calculation. You do not pay the higher rate on the entire gain just because part of it falls into the higher bracket. Instead, the portion of the gain that fits within your unused basic rate band is taxed at the lower rate (e.g., 10% or 18%), and only the remainder that spills over the £50,270 threshold is taxed at the higher rate (e.g., 20% or 24%).
No. This calculator is designed to model standard Capital Gains Tax for individuals based on typical residential property or share disposals. It does not calculate Business Asset Disposal Relief (formerly known as Entrepreneurs' Relief), which applies a flat 10% rate to qualifying business assets up to a lifetime limit. It also assumes you are a UK resident individual, not a trust or a company.