UK Capital Gains Tax Calculator

Updated for tax year 2026/27 Last reviewed 10 August 2026 Savings & Investments HMRC guidance on Capital Gains Tax

Capital Gains Tax is charged on the profit you make when you sell or give away an asset that has gone up in value — shares, property, antiques and more. The first £3,000 of gains each tax year is tax-free (the annual exempt amount).

Anything above the allowance is treated as your top slice of income and taxed at 18% in the basic rate band and 24% in the higher rate band. Enter your gains and other income to see your bill.

Your details

Your profit from selling assets, before the annual exempt amount
Salary, rental, savings and anything else taxable

Results

Capital Gains Tax
£2,160.00
Annual exempt amount of £3,000 applied
Gain after tax
£12,840.00
Chargeable gain
£15,000.00
Taxable gain
£12,000.00
At 18% (basic rate)
£2,160.00
At 24% (higher rate)
£0.00
Effective CGT rate
14.4%

How your CGT was calculated

Annual exempt amount (0%)£3,000.00
Taxable at 18%£12,000.00
Taxable at 24%£0.00
Total Capital Gains Tax£2,160.00

How the calculation works

We believe numbers should be transparent. Here is the formula behind this calculator.

Tax = (Gain − £3,000 allowance) × rate · 18% while it fits in your unused basic rate band, 24% above it

Worked example

Worked example: £15,000 gain in 2026/27

Other taxable income: £30,000 salary. Gain: £15,000.
After the Personal Allowance, £17,430 of your salary is taxable, so £20,270 of the basic rate band is unused.
The annual exempt amount removes the first £3,000 of the gain, leaving £12,000 taxable.
All £12,000 fits in the unused basic band → £12,000 × 18% = £2,160.

Examples at common levels

See how the numbers change at typical input levels, using the updated for tax year 2026/27 rates.

Scenario Capital Gains TaxGain after taxChargeable gainTaxable gainAt 18% (basic rate)At 24% (higher rate)Effective CGT rate
£10,000 gain, no other income
Allowance covers the first £3,000
£1,260.00£8,740.00£10,000.00£7,000.00£1,260.00£0.0012.6%
£15,000 gain + £30,000 salary
Fits mostly in the basic rate band
£2,160.00£12,840.00£15,000.00£12,000.00£2,160.00£0.0014.4%
£60,000 gain + £55,000 salary
Higher rate band
£13,680.00£46,320.00£60,000.00£57,000.00£0.00£13,680.0022.8%
£100,000 gain + £0 income
Large gain spreads across both rates
£21,018.00£78,982.00£100,000.00£97,000.00£6,786.00£14,232.0021.0%

Important assumptions

  • Uses England, Wales and Northern Ireland rates. The 18% and 24% rates apply to both property and other assets from 30 October 2024.
  • The annual exempt amount is £3,000 and is best used against gains that would be taxed at the higher rate.
  • Gains are treated as the top slice of income, after salary, savings and dividends.
  • Does not model Business Asset Disposal Relief, losses, transfers between spouses or foreign assets — see HMRC or a qualified accountant.

Rates & official sources

Every calculation is based on the official rates and rules published by GOV.UK and HMRC.

Frequently asked questions

How much Capital Gains Tax will I pay in 2026/27?

The first £3,000 of gains is tax-free. Above that you pay 18% on gains that sit in your unused basic rate band and 24% on the rest. Your salary affects which band your gains fall in.

Does the annual exempt amount change each year?

Yes. It was cut to £6,000 for 2023/24 and to £3,000 for 2024/25, where it stays for 2026/27. Always check the allowance for the year you dispose of an asset.

Is my main home exempt from Capital Gains Tax?

Usually yes. Selling your only or main home is normally exempt under Principal Private Residence relief, but part of the garden or periods of letting can trigger a charge. This calculator covers general assets.

When do I need to pay or report Capital Gains Tax?

For property, you usually must report and pay within 60 days of completion. For other assets you report through your Self Assessment return by 31 January after the tax year ends.

Related calculators

Related guides

New to the topic? Read a plain-English guide on savings & investments, with worked examples and tips.

These calculations are estimates for guidance only and are not professional financial, tax or legal advice. UK rates and rules change, so always verify important figures with official GOV.UK / HMRC information or speak to a qualified professional. See our full disclaimer.