Capital Gains Tax Calculator UK 2026

Work out exactly how much Capital Gains Tax (CGT) you owe in 2025/26 on the sale of property, shares, a business, or other assets. Enter your gain, income, and any reliefs, and get a full breakdown in seconds - including your effective tax rate, how much of your basic rate band is used, and whether Private Residence Relief or Business Asset Disposal Relief applies. Use alongside our take-home tax calculator to see your complete financial picture.

Key CGT Facts for 2025/26

💷
£3,000
Annual Exempt Amount - gains below this are CGT-free in 2025/26
🏠
18% / 24%
CGT rates for individuals - basic rate band / above basic rate band
🏢
14%
Business Asset Disposal Relief rate for qualifying disposals in 2025/26
📅
60 days
Deadline to report and pay CGT on UK residential property sales

Who Should Use This Calculator?

🏠

Property Sellers and Landlords

Calculate CGT on the sale of a buy-to-let, second home, or inherited property. Includes Private Residence Relief for partial occupation periods.

📈

Investors Selling Shares

Work out CGT on shares, funds, or investment trusts. See how your income affects which CGT rate applies and how much of your £3,000 allowance you use. Check your income tax band first.

🏢

Business Owners Selling Assets

Model whether Business Asset Disposal Relief applies to your sale and compare the 14% BADR rate versus standard CGT. The BADR rate rises to 18% from April 2026.

🧾

Self-Assessment Filers

Get the exact CGT figures you need for your Self Assessment return, including loss offsets, carry-forward relief, and how gains interact with income tax. Compare with our self-employed tax calculator if you run your own business.

⚛ Calculate Your Capital Gains Tax

Complete the fields below. Fields marked * are required. Results appear instantly below the form.

Your Income
Your total income before tax for the 2025/26 tax year. Used to determine which CGT rate applies.
2026/27 uses same rates; BADR rises to 18% from April 2026.
Your Capital Gain
All non-BADR assets use 18%/24% in 2025/26. BADR assets use 14%.
Choose how to enter your gain amount.
Proceeds minus your original cost, including any allowable improvement costs.
Reliefs and Deductions
How many months you owned the property in total.
Months you lived in the property as your only or main home (includes final 9 months of ownership automatically).
Capital losses from other disposals in the same tax year. Applied before the annual exempt amount.
Unused losses brought forward from prior years. Only used to reduce gain to the annual exempt amount level.
Any other taxable gains made this tax year from different assets. Used to calculate total gains and remaining annual exempt amount.
Trustees receive half the annual exempt amount (£1,500) and pay CGT at 24%.

How the CGT Calculator Works

1

Enter Your Income

Your gross income determines how much basic rate band remains unused, which directly sets your CGT rate at 18% or 24%.

2

Enter Your Gain

Enter your total gain directly, or let the calculator work it out from your sale proceeds, purchase cost, and all allowable deductions.

3

Apply Reliefs

Private Residence Relief, Business Asset Disposal Relief, annual exempt amount, and any capital losses are all applied in the correct HMRC order.

4

Get Your Bill

See your final CGT bill broken down by rate band, your effective tax rate, and personalised planning tips to reduce your liability.

Understanding Capital Gains Tax in 2025/26

Capital Gains Tax is charged on the profit (the "gain") you make when you sell or dispose of an asset that has increased in value. You only pay CGT on the gain, not the total sale proceeds. The annual exempt amount of £3,000 is deducted before any tax is calculated, and this allowance cannot be carried forward - if you do not use it in a tax year, it is lost.

How Income Affects Your CGT Rate

Your CGT rate is not fixed. HMRC adds your taxable gains to your income to determine which rate applies. If your income plus gains falls within the basic rate band (up to £50,270), your gains are taxed at 18%. Any portion above £50,270 is taxed at 24%. This means planning the timing of asset disposals relative to your income can make a meaningful difference to your bill. Our income tax band calculator can help you understand your position before making a disposal.

The 2024 Rate Changes

From 30 October 2024, CGT rates on shares and other assets rose from 10%/20% to 18%/24%, aligning them with residential property rates. This means the previous distinction between asset types (except BADR) no longer exists. If you are comparing an older estimate to this calculator, the rates will differ significantly for non-property assets.

Asset / Taxpayer Rate (Basic Rate Band) Rate (Above Basic Rate)
Residential Property 18% 24%
Shares and Other Assets 18% 24%
Business Asset Disposal Relief (BADR) 14% (flat, 2025/26) 14% (flat, 2025/26)
BADR from April 2026 18% (flat) 18% (flat)
Trustees 24% (flat) 24% (flat)

Private Residence Relief

If you sell a property that was your main home for part or all of your ownership period, Private Residence Relief (PRR) exempts the corresponding proportion of the gain. The final 9 months of ownership always qualify, even if you were not living there. Lettings relief was significantly restricted from April 2020 and now only applies if the tenant shared your living space.

Capital Losses and How They Work

Current-year losses must be offset against current-year gains before your annual exempt amount is applied. Losses from previous years are different: they are only used to reduce your net gain down to the annual exempt amount level, not below it, which preserves as much of your allowance as possible. You must report losses to HMRC to carry them forward. For more context on how disposals interact with your overall finances, see our PAYE tax breakdown calculator.

💡 60-Day Reporting Rule

If you sell a UK residential property and a CGT liability arises, you must report the gain and pay any tax owed within 60 days of completion. This applies even if you also need to include the gain in a Self Assessment return. Missing this deadline results in interest and penalties from HMRC.

Real Capital Gains Tax Examples

Scenario 1: Buy-to-Let Sale

Person: Sarah, secondary school teacher

Situation: Sells a buy-to-let flat she has never lived in. Owned for 10 years, never her main residence.

Gross Income: £38,000

Gain: £65,000

Annual Exempt Amount: -£3,000

Taxable Gain: £62,000

CGT Bill: £12,270 (£2,270 at 18% + £9,730 at 24%)

Sarah's income uses £25,430 of her basic rate band. The remaining £12,270 is used by the gain at 18%; the rest is taxed at 24%. Selling during a lower-income year (e.g., after retirement) could reduce the bill.

Scenario 2: Share Portfolio Disposal

Person: James, IT contractor

Situation: Sells shares with a gain of £30,000. Has £8,000 of carried-forward losses from a previous year.

Gross Income: £75,000

Gain: £30,000

Carried-Forward Losses Used: -£27,000

Annual Exempt Amount: -£3,000

Taxable Gain: £0

CGT Bill: £0

James uses just enough of his carried-forward losses to bring the net gain down to £3,000 (the AEA level). The remaining £1,000 of losses carry forward to a future year. See our contractor take-home pay calculator for the wider tax picture.

Scenario 3: Business Sale with BADR

Person: Priya, sole trader graphic designer

Situation: Sells her sole trader business after 8 years. First use of BADR lifetime allowance.

Gross Income: £20,000

Business Gain: £180,000

Annual Exempt Amount: -£3,000

Taxable Gain (BADR): £177,000

CGT Bill: £24,780 (at 14%)

Without BADR, Priya would pay £30,780 in CGT (18%/24%). BADR saves her £6,000 in 2025/26. If she waits until after 5 April 2026, the rate rises to 18%, costing an extra £7,080. Check our sole trader vs limited company calculator for ongoing tax planning.

Frequently Asked Questions

Data Sources and Accuracy

This calculator uses official HMRC figures for the 2025/26 tax year:

Calculation Methodology: Gains are calculated in the HMRC-prescribed order: gross gain - current-year losses - carried-forward losses (to AEA level only) - annual exempt amount - PRR/BADR. The result is then split across the basic and higher rate bands using remaining income headroom.

Last Updated: February 2026

Disclaimer: This calculator provides estimates for information purposes only and does not constitute tax advice. Individual circumstances vary. Always verify figures with HMRC or a qualified tax adviser before filing a return or making financial decisions based on this output.

Your Privacy and Data Protection

Your privacy matters. All calculations run entirely within your browser. No figures you enter are transmitted to any server or stored anywhere.

How it works: When you click "Calculate My CGT", your figures are sent to a server-side script that performs the calculation and immediately returns the result - no data is logged or retained. Your inputs are also saved temporarily in your browser's session storage to remember your entries if you navigate away, and cleared when you close your tab.

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