Capital Gains Tax calculator for property

If you sell a property that was never your main home, such as a second home, a buy-to-let or a house you inherited, you may owe Capital Gains Tax (CGT) on the rise in its value. This calculator estimates the tax for the 2026 to 2027 tax year (6 April 2026 to 5 April 2027) using the GOV.UK rates: 18% on the part of the gain that fits in your unused basic rate band and 24% on the rest, after the £3,000 tax-free allowance. Nothing you type is sent or saved.

How the calculator works

1. Your gain. The sale price, minus what you paid (or the probate value if you inherited it), minus the costs you can deduct.
2. The tax-free allowance. The first £3,000 of your gains in the tax year is tax-free. If other gains this year have used some of it, less is left for the property.
3. Your unused basic rate band. The basic rate band is £37,700. The calculator takes your income before tax, subtracts the £12,570 Personal Allowance, and treats the rest as using up the band. Any other taxable gains this year use up more of it.
4. The tax. The part of the gain that fits in what's left of the band is taxed at 18%, and the rest at 24%.

As a check, if you enter the figures from GOV.UK's own example (a gain of £52,600 and taxable income of £20,000, which is £32,570 before the Personal Allowance), the calculator gives the same answer: £10,842.

A worked example

You inherited a house with a probate value of £195,000 and sell it for £250,000. The estate agent and solicitor charge £6,000 between them. Your income this tax year is £30,000 and you have no other gains.

Step	Working	Amount
Gain	£250,000 − £195,000 − £6,000	£49,000
Tax-free allowance		−£3,000
Taxable gain		£46,000
Unused basic rate band	£37,700 − (£30,000 − £12,570)	£20,270
Tax at 18%	£20,270 × 18%	£3,648.60
Tax at 24%	£25,730 × 24%	£6,175.20
Capital Gains Tax		£9,824

If your income were £60,000, your basic rate band would already be used up, so the whole £46,000 would be taxed at 24%: £11,040.

Costs you can deduct

GOV.UK lets you deduct the costs of buying, selling and improving the property:

• Buying: solicitors' and surveyors' fees, and the Stamp Duty Land Tax you paid.
• Selling: estate agents' and solicitors' fees.
• Improvements: work that added to the property, such as an extension.

Normal maintenance, such as decorating, doesn't count. Keep the invoices, as you'll need the figures when you report the sale.

What this calculator doesn't cover

It's a simplified estimate for one person, one property and one tax year. It doesn't include:

• Private Residence Relief. If the property was your main home at any point, some or all of the gain may be tax-free, and the last 9 months of ownership always qualify. See do you pay tax when you sell your home?
• Other reliefs, such as Letting Relief.
• Losses. A loss you report is deducted from gains in the same tax year, and unused losses from earlier years can be used too. You have 4 years from the end of the tax year you made the loss to claim it.
• Sales by executors. If the personal representatives sell during the administration of the estate, the tax is 24% and different allowance rules apply. See Capital Gains Tax on inherited property.
• Gift Aid and pension contributions. These can extend your basic rate band, so more of the gain may be taxed at 18%.
• Joint ownership. Enter only your share of the prices and costs, because each owner works out the gain on their own share.
• Non-UK residents, who must report every UK property sale within 60 days, even when there's no tax to pay.

If you're a Scottish or Welsh taxpayer, you can still use it. HMRC works out the basic rate band for CGT as if you weren't, so the UK-wide £37,700 band applies.

Reporting and paying within 60 days

If you're a UK resident and sell a UK residential property with CGT to pay, you must report the sale and pay the tax within 60 days of completion, using HMRC's online service. You may have to pay interest and a penalty if you're late. You don't need to report this way if your total gains are within the tax-free allowance.

You'll need the property's address, the dates you bought it, exchanged contracts and completed, what you paid and what you sold it for, your costs and any reliefs you're claiming.

HMRC's own tools

• Tax when you sell property explains the rules and links to HMRC's Calculate Capital Gains Tax on property service. You can't use that service if you sold land or business premises, sold other chargeable assets (such as shares) in the same tax year, reduced your share of a property you still own jointly, are claiming reliefs other than Private Residence Relief or Letting Relief, or are selling as a company, agent, trustee or personal representative.
• Report and pay your Capital Gains Tax is where you report a UK property sale within the 60 days.

If any of the points above apply to you, speak to an accountant or tax adviser, or contact HMRC, before you rely on the figure.