Capital Gains Tax Calculator
Calculate the CGT due on the sale of property, shares or other assets at the 2025/26 rates
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Based on UK CGT rates for the 2025/26 tax year (rates aligned 30 October 2024)
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CGT on a property sale is reportable within 60 days of completion. Get the calculation, reliefs and HMRC report handled by our tax planning team before the clock starts.
Understanding Capital Gains Tax
Capital Gains Tax (CGT) is the tax you pay on the profit when you sell, give away or otherwise dispose of an asset that has gone up in value. You only pay tax on the gain, not on the full amount you receive.
Most people pay CGT on the sale of second homes, buy-to-let properties, shares held outside an ISA, crypto, and stakes in their own business. Disposals of your main home are usually covered by Private Residence Relief and fall outside CGT.
Current CGT Rates (2025/26)
From 30 October 2024 the main CGT rates were aligned with residential property rates. For the 2025/26 tax year the rates are:
- 18% on gains within your unused basic rate band
- 24% on gains above the basic rate band
- £3,000 annual exempt amount (down from £6,000 in 2023/24 and £12,300 in 2022/23)
The 18% / 24% split now applies equally to residential property, shares, crypto and other chargeable assets. To work out which rate applies, you add the taxable gain on top of your income and see how much fits inside the basic rate band.
Business Asset Disposal Relief (BADR)
BADR cuts the CGT rate on qualifying business sales. The rate is being increased in stages:
- 10% up to 5 April 2025
- 14% from 6 April 2025 (2025/26)
- 18% from 6 April 2026 (2026/27)
A £1 million lifetime limit applies to gains qualifying for BADR. Investors' Relief uses the same rate but has a separate £1 million lifetime cap.
How Capital Gains Tax is Calculated
The calculation runs in four steps:
- Take the sale price (or market value if it's a gift)
- Subtract the original purchase cost and any allowable costs (legal fees, stamp duty paid, capital improvements)
- Subtract the £3,000 annual exempt amount
- Apply 18% to gains in the basic rate band and 24% above it
Example: A buy-to-let bought for £250,000 and sold for £350,000, with £5,000 of legal fees and improvements. Total gain £95,000. After the £3,000 exempt amount, £92,000 is taxable. For a higher-rate taxpayer, the tax bill is £92,000 × 24% = £22,080.
Reporting and Payment Deadlines
Residential property: 60-day rule
If you sell a residential property at a gain you must report and pay CGT within 60 days of completion using HMRC's online CGT on UK Property service. Missing the deadline triggers penalties, even if you have no other CGT to pay.
Other gains: through Self Assessment
Gains on shares, crypto and other assets are reported through your normal Self Assessment return. The tax is due by 31 January after the end of the tax year.
Common reliefs to consider
- Private Residence Relief — usually covers the sale of your main home
- Lettings Relief — limited relief if you let part of your main residence
- Spousal transfers — assets between spouses or civil partners are no-gain, no-loss
- Capital losses — can be offset against gains in the same year or carried forward
Reliefs often save more tax than the calculator alone suggests. Our tax planning service works out the optimal disposal structure before you sign anything.
Selling Property, Shares or a Business?
We model the CGT position before you commit, claim every relief you qualify for, and file the 60-day return on residential disposals so you never miss the deadline.