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UK Capital Gains Tax (CGT) on Shares & Investments — Calculator

Estimate UK Capital Gains Tax (CGT) liability on disposals of shares, investments and residential property. This tool follows HM Revenue & Customs (HMRC) guidance and shows how gains above the Annual Exempt Amount are taxed. Select a tax year to load the official Annual Exempt Amount and basic-rate threshold (editable).

Page updated:
Jul 14, 2026
Tool version:
v1.2.0

Overview

Estimate UK Capital Gains Tax (CGT) on disposals of shares, investments and residential property. This calculator provides illustrative estimates following HM Revenue & Customs (HMRC) guidance.

Results

Taxable gain (GBP)

$0.00

Estimated CGT due (GBP)

$0.00

Calculation notes

About this tool

Author: Tax Content Team (Chartered Tax Adviser, senior technical writer). Last updated: 2026-01-03. Data sources: HM Revenue & Customs — Capital gains: https://www.gov.uk/capital-gains-tax; HMRC rates and allowances: https://www.gov.uk/capital-gains-tax/rates. This tool provides estimates only. See disclaimer and help links for privacy and support.

How to read the result

What it means
The displayed value is an estimate based on your inputs. It represents the calculated scenario under current assumptions, not a guaranteed amount.
Next step
Use the result as a starting point. Adjust parameters to compare scenarios and validate with a professional when needed.
Calculation limits
The model uses simplified formulas and cannot account for all variables in your specific case (local regulations, personal conditions, temporal changes).

Methodology

Gross gain = proceeds - cost basis - allowable costs. Private Residence Relief (PRR) can reduce the chargeable gain amount (enter the PRR exempt portion if relevant).

The Annual Exempt Amount is then deducted to determine taxable gain.

A portion of the taxable gain may be taxed at a lower CGT rate where it falls within any remaining basic-rate income band. The remaining portion is taxed at the higher-rate CGT. For qualifying business disposals, Business Asset Disposal Relief (BADR) can apply: indicate BADR applies and the eligible portion, which the tool taxes at the BADR rate (10%) up to the provided BADR limit. Rates used are standard CGT rates: investments 10%/20%; residential 18%/28%. BADR portion is taxed at 10%.

Glossary+
Gross gain

Proceeds minus the cost basis and allowable disposal costs, before subtracting reliefs and the Annual Exempt Amount.

Annual Exempt Amount

The tax-free allowance for capital gains in a tax year. Gains above this amount are subject to CGT.

Basic-rate band

The portion of income taxed at the basic income tax rate. Remaining basic-rate band determines how much of a gain is taxed at the lower CGT rate.

Private Residence Relief (PRR)

A relief which can exempt part or all of a gain on the sale of a qualifying main residence. Users should estimate the PRR exempt portion if applicable.

Business Asset Disposal Relief (BADR)

A relief (formerly Entrepreneurs' Relief) that, if qualifying, taxes eligible gains at a reduced rate (10%) up to the user's available BADR lifetime limit. The tool accepts a BADR portion to apply this preferential rate.

Key takeaways

This calculator gives an estimate of CGT on UK shares, investments and residential property following HMRC principles: apply allowable costs, optional reliefs (if indicated), subtract the Annual Exempt Amount, and split the taxable gain between basic- and higher-rate bands.

For definitive calculations, reporting obligations and relief eligibility, consult HMRC guidance or a qualified tax adviser.

Worked examples

Example: Sale of Listed Shares

Sold shares for £10,000 with acquisition cost £4,000 and allowable costs £200. Taxable income before the gain is £30,000. Annual Exempt Amount £6,000.

Interpretation

Gross gain = £5,800; taxable gain after exempt = £0, so no CGT payable in this example.

Example: Residential Property Disposal

Sold a residential property for £250,000 with purchase cost and allowable costs totalling £180,000. Taxable income before the gain is £40,000. Annual Exempt Amount £6,000. Assume partial PRR applied of £6,000 for illustration.

Interpretation

Gross gain = £70,000; PRR £6,000 reduces the chargeable gain; taxable gain after Annual Exempt Amount is £58,000. Portion falling in remaining basic-rate band is taxed at 18%; remainder at 28%.

Frequently asked questions

How does the calculation work?

The calculator computes gross gain, applies optional reliefs that reduce the chargeable gain (e.g. PRR), deducts allowable costs and the Annual Exempt Amount, then allocates the taxable gain across basic- and higher-rate bands based on your taxable income. BADR changes the rate applied to qualifying business disposals and is handled as a preferential-rate portion in this tool.

Why should I use this calculator?

This tool provides an estimate to support planning and understanding potential CGT liability. It is not a substitute for personalised professional tax advice.

Are the rates and allowances kept up to date?

Select a tax year to pre-fill common official values. Values are editable; always verify against HMRC announcements. Direct HMRC links are provided in the citations section.

What reliefs are included?

This tool supports PRR (reduces chargeable gain) and BADR (applies a preferential 10% rate up to the user-provided BADR limit). It does not automatically calculate full eligibility rules for every relief — consult HMRC guidance or a tax adviser to confirm eligibility.

Sources & references

  1. HM Revenue & Customs (HMRC) — Capital gains: https://www.gov.uk/capital-gains-tax
  2. HMRC — Capital gains tax rates and allowances: https://www.gov.uk/capital-gains-tax/rates

Quality & oversight

Maintained by
Ugo Candido, MBA
Page updated
Jul 14, 2026
Tool version
v1.2.0

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