UK Property Capital Gains Tax Calculator
Estimate your capital gains tax when selling UK property. Enter your figures below and click calculate.
This tool gives an estimate only. Tax rules can change and individual circumstances vary. Confirm figures with HMRC guidance or a qualified adviser.
How UK capital gains tax on property works
If you sell a UK property that is not fully covered by private residence relief, you may have to pay Capital Gains Tax (CGT) on the profit. The “gain” is usually not just sale price minus purchase price. HMRC lets you deduct a range of allowable costs before tax rates are applied.
A practical way to think about the calculation is:
- Start with sale proceeds.
- Subtract purchase cost and allowable acquisition/disposal costs.
- Subtract eligible improvement costs and allowable reliefs/losses.
- Apply your annual exempt amount.
- Tax the remaining gain at the correct CGT rates for your income band.
What this property CGT calculator includes
The calculator above is designed for a fast estimate and includes the core inputs most people need:
- Purchase price and sale price
- Buying and selling costs (for example legal fees, estate agent fees, and some transaction costs)
- Capital improvements (not ordinary repairs)
- Reliefs and brought-forward capital losses
- Ownership share for jointly owned property
- Taxable income to split the gain between lower and higher CGT rates
Rates used in this tool
For residential property, this calculator uses 18% and 24% as standard CGT rates, with the split based on how much of your basic rate band remains after your taxable income. For other chargeable assets, the tool uses 10% and 20%.
Allowable costs people often miss
Many sellers overestimate tax because they forget valid deductions. Common examples include:
- Solicitor/conveyancing fees on purchase and sale
- Stamp Duty Land Tax paid when buying (where allowable for gain computation)
- Estate agent and advertising fees for disposal
- Capital enhancement works such as extensions or major structural upgrades
Routine maintenance and repairs usually do not count as capital improvements for CGT purposes.
Example calculation (quick walkthrough)
Imagine you sell a rental flat for £420,000 that you bought for £280,000. You had £6,000 buying costs, £7,000 selling costs, and £22,000 qualifying improvements.
- Gross gain: £420,000 - (£280,000 + £6,000 + £7,000 + £22,000) = £105,000
- Less losses/reliefs (if any)
- Less annual exempt amount (for example £3,000)
- Tax the balance at 18%/24% depending on your unused basic rate band
Your exact bill can differ if private residence relief, letting relief, non-resident rules, or trust/company rules apply.
How to reduce capital gains tax legally
1) Keep strong records
Documentation is essential. Save invoices, completion statements, legal bills, and proof of improvement works. Missing paperwork can mean losing deductions.
2) Use losses where available
Brought-forward capital losses can reduce taxable gain. Make sure losses are properly reported and available to claim.
3) Consider timing and ownership structure
Timing a disposal across tax years, or ensuring gains are allocated correctly between joint owners, can materially affect tax. Always obtain professional advice before making structural changes.
Reporting and payment deadlines
UK residential property disposals that create a CGT liability usually have strict reporting and payment deadlines. Missing deadlines can trigger interest and penalties. Check the current HMRC deadline rules at the time of sale, since timelines and process details can change.
Frequently asked questions
Do I pay CGT on my main home?
Many people get full or partial private residence relief on their main home, so CGT may be reduced or eliminated.
Are mortgage payments deductible from the gain?
No. Mortgage repayments are not a deductible capital cost when calculating CGT gain.
What if the property is jointly owned?
Each owner is generally taxed on their share of the gain. Use the ownership share field to estimate your portion.