UK Capital Gains Tax Calculator

Estimate the Capital Gains Tax (CGT) you owe for 2026/27 on shares, property and other assets — after your £3,000 tax-free allowance.

Your gain

Sale proceeds (what you received)

Allowable costs (what you paid + selling costs)

Original purchase price plus buying and selling costs, e.g. fees and stamp duty.

Other taxable income

Your taxable income from work, pensions etc. — decides whether gains are taxed at 18% or 24%.

Asset type

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Chargeable gain

£—

Tax-free (annual exempt amount)£—

Gain taxed at 18%£—

Gain taxed at 24%£—

Tax due: £—

Losses and other reliefs are not modelled — this is an estimate.

Rates for 2026/27: GOV.UK — Capital Gains Tax rates and allowances (18%/24% individuals; £3,000 annual exempt amount).

How it works

Your chargeable gain is your sale proceeds minus your allowable costs. The first £3,000 of gains in a tax year is tax-free (the annual exempt amount). The rest is taxed at 18% while your gains sit within the unused basic-rate band, and at 24% above that. Your other taxable income determines how much basic-rate band is left for your gains.

Example calculation

You sell shares for £50,000 that originally cost £30,000 (including costs), with other taxable income of £25,000:

Chargeable gain: £20,000
Minus annual exempt amount: − £3,000 → taxable gain £17,000
Your £25,000 income leaves £12,700 of basic-rate band → £12,700 × 18% = £2,286
Remaining £4,300 × 24% = £1,032
Total CGT: ≈ £3,318

Example is illustrative for the 2026/27 tax year. Losses and reliefs are not modelled.

Methodology & formula

Chargeable gain = proceeds − allowable costs.
Taxable gain = chargeable gain − annual exempt amount (£3,000).
Basic-rate portion = min(taxable gain, max(0, £37,700 − other taxable income)).
Tax = (basic-rate portion × 18%) + (taxable gain − basic-rate portion) × 24%.

Assumptions: you are an individual UK resident, no losses carried forward, no other reliefs claimed, and no chargeable gain from a qualifying new resident FIG/OWR regime.

UK-specific information

Annual exempt amount: £3,000 for individuals for 2026/27, frozen from the previous year. GOV.UK · 2026/27
Rates: from 6 April 2026, individuals pay 18% on gains within the basic-rate band and 24% above it — the same rates apply to residential property and other assets. GOV.UK · 2026/27
Business Asset Disposal Relief: qualifying gains are taxed at a flat 18% in 2026/27 (up from 14% in 2025/26), with a £1m lifetime allowance. GOV.UK · 2026/27
Your main home: usually exempt under Private Residence Relief — this calculator is for assets that attract CGT.
Reporting: gains above the allowance must be reported via a tax return or the Capital Gains Tax service within 60 days for UK property sales.

Frequently asked questions

What is the annual exempt amount?

The tax-free amount of capital gains you can make each tax year before paying CGT — £3,000 for individuals in 2026/27. Gains above this are taxed.

Do I pay 10% or 20% CGT?

No. From 30 October 2024 the old 10%/20% rates were replaced. For 2026/27 individuals pay 18% on gains within the basic-rate band and 24% above it.

What counts as allowable costs?

The price you paid, plus buying and selling costs such as broker fees, legal fees and Stamp Duty. Improvements to an asset can usually also be deducted.

How do losses affect this?

Losses are deducted from gains before the annual exempt amount, and unused losses can be carried forward. This calculator does not model losses — deduct them from your proceeds first.

Is my main home taxed?

Usually no — Private Residence Relief means your main home is exempt. CGT applies to second homes, rental properties, shares and other investments.

What is Business Asset Disposal Relief?

A relief taxing qualifying business disposals at a flat 18% in 2026/27, subject to a £1m lifetime limit. It replaces Entrepreneurs' Relief.

Related calculators

Dividend Tax Calculator · UK Income Tax Calculator · Stamp Duty Calculator · Investment Return Calculator · Home

Sources

GOV.UK — Capital Gains Tax rates and allowances: gov.uk (2026/27)

Casvia provides educational calculators and general information. It does not provide personal financial, tax or investment advice. Rules and thresholds can change — always check the latest official guidance.