Allowable costs come before the tax rate question
The chargeable gain is worked out after allowable buying, selling and capital-improvement costs are deducted. If those costs are left out, the tax estimate is usually overstated from the start.
2026/27 Property CGT Planner
CGT calculator for UK residential property sales
Estimate residential property Capital Gains Tax from the sale price, allowable costs, Private Residence Relief, capital losses, annual exempt amount and the 18% / 24% rate split.
Property CGT estimatePRR and rate-split supportAllowable costs separated clearly
Annual Exempt Amount
2026/27 annual exempt amount: £3,000
Residential Property Rates
18% inside the unused basic-rate band and 24% above it
Reporting Deadline
UK residential property CGT is usually reported and paid within 60 days where tax is due
Planner
Start with the sale figures and the tax position that applies to you
Build the estimate from the property sale, then layer in allowable costs, reliefs, losses and taxable income so the result reflects the disposal you are actually reviewing.
Property sale figures
£
£
£
Use allowable acquisition costs such as stamp duty, solicitor fees and survey fees that form part of the capital-gains calculation.
£
Use disposal costs such as estate-agent and legal fees on the sale.
£
Use capital improvements only. Routine repairs and maintenance belong outside this line.
Relief and tax position
How was the property used?
£
Use allowable capital losses available to offset this gain before the annual exempt amount is applied.
£
Enter taxable income after allowances and reliefs, before this property gain. This is used to split the gain between the 18% and 24% residential property rates.
£
Use this only if relief-at-source pension contributions or Gift Aid extend the amount of gain that can still sit in the 18% band.
Property CGT Estimate
Gross Gain
£150,000Allowable Costs
-£23,000Gain After Costs
£127,000Annual Exempt Amount Used
-£3,000Current annual exempt amount: £3,000
Taxable Gain
£124,000Estimated CGT Payable
£29,760Net Gain After CGT
£97,24018% / 24% Rate Split
Standard Basic-Rate Band
£37,700Adjusted Basic-Rate Band
£37,700No Gift Aid or relief-at-source pension extension entered.
Taxable Income Before Gain
£45,000Unused Basic-Rate Band
£0Gain Taxed At 18%
£0Estimated tax from this slice: £0
Gain Taxed At 24%
£124,000Estimated tax from this slice: £29,760
Effective Tax Rate
23.43%Before you rely on the estimate
- Only capital improvements belong in the improvement field. Routine repairs and maintenance should be left out.
- Letting relief is not included in this planner. It is limited to narrower shared-occupancy cases, not standard whole-property letting.
- Where CGT is due on a UK residential property sale, the return and payment are usually due within 60 days of completion.
Key Inputs
Four parts of the calculation that usually change the outcome
The headline rate is only one part of the answer. These are the inputs that often make the biggest difference on a residential property sale.
Private Residence Relief can erase or reduce the gain
If the property was your only or main home throughout ownership, full relief can remove the gain. If it was your home for only part of the ownership period, the apportionment and final 9 months can materially change the taxable amount.
The gain can be split between 18% and 24%
The whole taxable gain does not automatically sit at one rate. Part of the gain may still fall inside the unused basic-rate band before the rest moves into the 24% residential property rate.
Losses and band extensions still matter
Allowable capital losses reduce the gain before the annual exempt amount is applied, and Gift Aid or relief-at-source pension contributions can extend the basic-rate band available for gains.
Worked Examples
Two illustrations that show how the calculation moves
Use these examples to see why relief, income and ownership history can change the tax outcome even when the sale price looks similar on paper.
| Taxable income before gain | £20,000 |
|---|---|
| Basic-rate band used for gains | £37,700 |
| Taxable gain after the allowance | £49,600 |
| Amount taxed at 18% | £17,700 |
| Amount taxed at 24% | £31,900 |
| Estimated CGT payable | £10,842 |
Partial main-home illustration
On an illustrative gain of £120,000 where the property was owned for 180 months and lived in as the main home for 90 months, the planner gives relief for 99 months. That includes the lived-in period plus the current final 9 months.
Private Residence Relief
£66,000
Taxable gain after relief and allowance
£51,000
This is a simple illustration of how part-occupation changes the chargeable gain. A property that was your home for only part of ownership should not be treated the same way as a pure buy-to-let sale.
Special Cases
When a property sale needs fuller tax advice
Some disposals are still too fact-specific for a quick calculator. Use these prompts to spot when you should step beyond a standard residential estimate.
Letting relief only applies in narrower cases
Letting relief is not a general deduction for every former rental property. It is now limited to much narrower shared-occupancy situations than many older pages imply.
Trust, company and non-resident cases need separate treatment
Those cases can involve different reporting routes, rates or relief conditions, so they should not be folded into a standard individual residential estimate.
Multiple disposals need a wider review
This calculator is designed around one residential property sale. If several gains, losses or ownership structures interact in the same tax year, the calculation needs a wider review.
Repairs and improvements still need to be separated carefully
Only qualifying capital improvements belong in the calculation. Routine repairs and maintenance should not be used to reduce the gain.
Next Tools
Use the next tool once the sale position is clearer
The best follow-on route depends on whether you are comparing a sale, a replacement purchase or the wider cash effect of the transaction.
Buy-to-Let Calculator
Move here if the real question is whether the property still works as a retained investment rather than a disposal.
Stamp Duty Calculator
Use the SDLT planner if the sale feeds into a replacement purchase and you need the next tax layer in the budget.
Fees and Costs Calculator
Bring legal, valuation and moving costs into view if the property transaction is part of a wider cash-planning decision.
Property CGT Guide
Read the guide if the disposal needs clearer treatment of PRR, allowable costs, rate bands and the 60-day reporting point.
Frequently Asked Questions
Do you usually pay CGT when you sell your main home?
Not usually if the property qualified as your only or main home throughout ownership. Full Private Residence Relief can remove the gain in that situation, while partial relief can apply where the property was your main home for only part of the ownership period.
What residential property CGT rates are used here in 2026/27?
The calculator uses the 2026/27 residential property rates of 18% for the part of the taxable gain that still sits inside the unused basic-rate band and 24% for the part above it. It also uses the current annual exempt amount of £3,000.
What costs can be deducted before CGT is worked out?
You can usually deduct allowable buying costs, selling costs and capital improvement costs when working out the gain, and you can also use allowable capital losses. General repairs and maintenance are treated separately from capital improvements.
When do you report and pay CGT on UK residential property?
UK residents usually need to report and pay Capital Gains Tax on residential property within 60 days of completion when tax is due. That sits alongside, not instead of, any later Self Assessment reporting obligations.
Does this calculator include letting relief?
No. Letting relief is not included here because it now applies in much narrower shared-occupancy situations than many older mortgage websites suggested, not across ordinary whole-property letting scenarios.