Capital Gains Tax on Property
Your sale price, purchase costs, years owned, and Private Residence Relief. Calculate your CGT bill on selling a residential property under 2026/27 rules — 18% or 24%, with the 60-day reporting deadline front and centre.
When does CGT apply to a property sale?
When you sell a residential property for a gain, you're liable for Capital Gains Tax — unless it qualifies for Private Residence Relief (PRR). Your main residence — the property where you live as your primary home — is completely exempt from CGT for the entire period you owned it as your main home, plus the final nine months of ownership, even if you had moved out by then. Those final nine months count only if the property was your only or main home at some point; a property you never lived in gets no Private Residence Relief. This is a powerful relief: many property sales incur zero tax because of PRR, even though the property has gained substantially in value.
Private Residence Relief — how the fraction works
PRR is calculated as a fraction: the months the property was your only or main home, plus any of the final nine months of ownership not already inside that period (the final nine months count only if it was your main home at some point), divided by the total months you owned it. The final nine months are never counted twice. If you owned a property for 20 years (240 months), lived in it for the first 15 years (180 months) and then let it, PRR covers 189 months (180 + the final 9). That's 189/240 = 78.75% of your gain tax-free, and the remaining 21.25% is taxable. If instead you let it for the first 5 years and then lived in it for the last 15 years up to the sale, the final nine months are already part of your 180 months as a main home, so PRR covers 180/240 = 75%. The calculator asks which way round it was. If you lived there in the middle of your ownership and moved out more than nine months before the sale, choose "First".
Letting Relief — a narrow survivor
Letting Relief was sharply curtailed in April 2020. Today it's available only if you lived in the property at the same time as a tenant — meaning you let part of your home as residential accommodation while living in the rest of it, rather than simply renting the whole thing out. A lodger who shares your living space does not count as letting out part of your home, so Private Residence Relief is not reduced and Letting Relief is not needed. The relief is the lowest of three amounts: your Private Residence Relief, £40,000, and the gain from the let part. Joint owners each work it out on their own share of the gain. The calculator treats all of the gain left after Private Residence Relief as gain from the let part, which overstates the relief if some of that gain comes from a time when you did not live there. If you were a buy-to-let landlord from day one, or if you moved out entirely before letting, you don't qualify. Check carefully whether your property qualifies before relying on this relief.
Which rate applies: 18% or 24%
For 2026/27, gains on residential property are taxed at 18% or 24%. Since 30 October 2024 the main rates for most other assets have been the same, after rising from 10% and 20%. Which rate you pay depends on your income. Take your taxable gain (after the £3,000 annual exempt amount) and add it on top of your taxable income, which is your income after the Personal Allowance. The part of the gain that falls within the basic rate band (the first £37,700 of taxable income in 2026/27) is taxed at 18%, and any part above it at 24%. For example, with income of £40,000 your taxable income is £27,430, leaving £10,270 of the band. A £50,000 taxable gain is then taxed at 18% on £10,270 and 24% on £39,730: £11,384 in total. The calculator does this split from the income you enter, using the standard £12,570 Personal Allowance, which falls by £1 for every £2 of adjusted net income over £100,000.
Your inputs
CGT calculation breakdown
| Item | Amount |
|---|---|
| Sale price | £0 |
| Less: purchase price | £0 |
| Less: purchase costs (SDLT, legal, survey) | £0 |
| Less: capital improvements | £0 |
| Less: selling costs (legal, agent) | £0 |
| Gross gain | £0 |
| Less: Private Residence Relief (PRR) | £0 |
| Less: Letting Relief (if applicable) | £0 |
| Gain after reliefs | £0 |
| Annual Exempt Amount (AEA) — £3,000 per person | £0 |
| Taxable gain | £0 |
| Tax at 18% / 24% | £0 |
| Net proceeds (sale price less CGT) | £0 |
If you are a UK resident with Capital Gains Tax to pay on a UK residential property, you must report the sale to HMRC and pay the tax within 60 days of completion of sale. HMRC can charge interest and a penalty if you report or pay late. If you are not a UK resident, you must report every sale or disposal of UK property or land by the deadline, even if there is no tax to pay. Mark your calendar: 60 days from completion is your deadline — set the reminder at exchange so you don't miss it.
If you're selling jointly with your spouse, the gain can be split between you. Each person gets a separate £3,000 Annual Exempt Amount — so you can jointly shelter £6,000 of gain tax-free instead of £3,000. More importantly, if one spouse has unused basic-rate band, you can load more gain onto them at 18% instead of 24%. This is automatic if you've held the property as joint owners. If you owned it individually, a no-gain-no-loss transfer to your spouse before sale — allowed under spousal relief — lets you then sell jointly and split the gain.
Capital improvements vs repairs
Capital improvements (allowed deduction): A new extension, loft conversion, fitted kitchen, new bathroom, double glazing, or central heating. These add to the property's value and are deductible from your gain. Repairs (NOT allowed): Fixing a leaky roof, redecorating, replacing broken windows, repainting. These maintain the property but don't materially enhance its value and are not deductible. The dividing line can be blurry — when in doubt, consult a tax specialist.
If you claim £50,000 in capital improvements, HMRC can challenge you. Keep all invoices, receipts, architect's drawings, and building regulation certificates. Improvements made more than a year before sale are easier to substantiate; last-minute work raises eyebrows. A surveyor's report documenting the property's condition before and after improvements can be helpful too.
This is not tax advice
This calculator illustrates the core mechanism of CGT on residential property sales but omits many edge cases, reliefs, and special rules. Your circumstances may differ: non-resident status, overseas property, joint ownership complexities, trust interests, or partial business use can all affect your liability. The tax figure assumes the standard Personal Allowance and basic rate band, and no other gains or losses in the same tax year. Always consult a qualified tax adviser or accountant before a major sale. HMRC guidance is available at gov.uk/capital-gains-tax.
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