Capital Gains Tax on Property Calculator UK 2025/26

Reviewed by Mustafa Bilgic
UK Calculator Editor · Updated May 2026

How CGT on UK property is calculated in 2025/26

Capital Gains Tax on UK residential property is the difference between sale proceeds and the property's allowable cost base, taxed at 18% or 24% depending on where the gain falls within your income bands. The annual exempt amount of £3,000 is deducted before the rate is applied.

Allowable acquisition costs include the original price paid, SDLT/LBTT/LTT, conveyancing legal fees, surveyor fees and Land Registry charges. Allowable disposal costs include estate agent commission, legal fees and any required Energy Performance Certificate. Capital improvements during ownership are added to the cost base — but routine maintenance and decoration are not.

If you ever lived in the property as your main residence, Private Residence Relief reduces the gain in proportion to that period plus the final 9 months. Letting Relief was abolished from 6 April 2020 except in shared-occupancy situations.

60-day reporting and payment

Since April 2020 (extended to 60 days in October 2021), residential property CGT must be reported and paid within 60 days of completion — not waited until Self Assessment in January. The CGT return uses HMRC's online property service via gov.uk and requires a Government Gateway account.

Failure to report on time triggers a £100 fixed penalty, daily £10 penalties after 3 months, and 5% of the unpaid tax at 6 and 12 months. The figures still appear on the Self Assessment return at year-end so HMRC can reconcile.

BTL sold by higher-rate landlord

Buy 2014 £180,000 + £6,500 acquisition costs. Sell 2026 £295,000 − £6,000 sale costs. New kitchen/bathroom £14,000. Gain = £88,500. After £3,000 AEA = £85,500. Tax at 24% = £20,520.

Mixed-rate sole trader

Self-employed landlord with £42,000 trading income, basic-rate band £8,270 left. Property gain £18,000 after AEA. £8,270 at 18% (£1,489) + £9,730 at 24% (£2,335) = £3,824 total CGT.

Former main residence converted to BTL

Owned 12 years (144 months); 8 years lived in (96 months) + 9 months final period = 105 months PRR. Gross gain £100,000. PRR exempt portion: 105/144 × £100k = £72,917. Taxable: £27,083 minus £3,000 AEA = £24,083. Higher-rate tax at 24% = £5,780.

Common mistakes to avoid

• Forgetting the 60-day reporting window — most landlords default to Self Assessment timing, racking up penalties.
• Treating decoration as a capital improvement — only structural and like-for-like-replacement-with-upgrade qualifies.
• Missing the spousal transfer no-gain-no-loss treatment — half-share to a basic-rate spouse before sale doubles the AEA and may halve the rate.
• Forgetting brought-forward capital losses — fully deductible against CGT.
• Misreporting the disposal value when the sale was at undervalue to family — HMRC uses market value.

When to use this calculator

Use months before the sale to plan the disposal. Strategies include transferring half the property to a basic-rate spouse, harvesting capital losses elsewhere, deferring sale to a year of lower income, or offsetting against EIS deferral relief.

How this differs in Scotland, Wales and Northern Ireland

CGT is a UK-wide tax — Scotland, Wales and NI use the same 18%/24% residential rates and £3,000 AEA. Welsh and Scottish income tax bands differ; HMRC asks for your country of residence to apply the correct income band when computing the basic/higher slice.

When this calculator is and isn't the right tool

The Capital Gains Tax on Property Calculator UK 2025/26 above is built for the most common UK 2025/26 scenarios in this tax area. It will be the right tool when your situation maps cleanly onto the inputs — single property or simple aggregation, standard HMRC rates and bands, and individual taxpayer (rather than complex trust or partnership structures). It is informational and does not replace tailored advice from a chartered tax adviser, especially for transactions above £500,000, cross-border situations, or where reliefs interact with each other. For year-end filings, always reconcile with HMRC's own free calculators on gov.uk before pressing submit on Self Assessment.

Closely related calculators

• Holiday Let CGT Calculator — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Property Flipping Tax Calculator — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• CGT on Property Calculator — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Main Residence Relief — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• 60-day CGT Reporting — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.

Glossary of UK property tax terms

CGT

Capital Gains Tax — UK tax on profit from selling assets, including residential property.

AEA

Annual Exempt Amount — £3,000 in 2025/26, deducted from gain before tax.

PRR

Private Residence Relief — exempts gains on the period a property was your only or main residence.

BADR

Business Asset Disposal Relief — formerly Entrepreneurs' Relief, 10% rate. Not available on residential property.

60-day rule

UK residential property CGT must be reported and paid within 60 days of completion via HMRC online.

Tax planning checklist

1. Confirm the figures input above match your actual position — purchase contract, mortgage offer or completion statement.
2. Cross-check the year (2025/26) — figures change every April. The tax year 2026/27 starts 6 April 2026.
3. Use HMRC's official calculator at gov.uk for the final filing figure; this calculator is informational.
4. Keep records for at least 6 years — HMRC's normal enquiry window. 21 years for fraud investigations.
5. Discuss any unusual transaction (joint purchase, gift, divorce settlement, trust) with a qualified tax adviser.
6. Submit your return online via Government Gateway — paper deadlines are earlier and penalties harsher.