Capital gains tax on a property sale, with the full cost basis — purchase, improvements and selling costs.
The sale, the purchase, and everything that counts as cost
The two prices
Gross price the property sold for, in your local currency.
What you originally paid (your acquisition cost or cost basis).
What adds to your cost basis
Money spent on improvements that add value (not routine repairs).
Agent commission, legal fees, and other costs of selling.
Exemption and rate
Any tax-free allowance or relief you qualify for (verify locally).
%
Your applicable CGT rate as a percent. Rates vary by country, income, and holding period — verify with a tax professional.
Estimated Capital Gains Tax
30,000
Taxable gain multiplied by your CGT rate.
Formula verified 12 September 2026
Capital Gain
150,000
Sale price minus purchase, improvements, costs, and exemption.
Net Gain After Tax
120,000
Your gain after the estimated tax is paid.
Taxable Gain
150,000
The gain that is actually taxed (never below zero).
Total Cost Basis
350,000
Purchase price plus improvements plus selling costs — the figure the sale price is measured against, and the reason the gain is smaller than the two prices suggest.
From sale price to after-tax gain. Verify the rate and reliefs locally.
Item
Amount
Sale price
500,000
Cost basis + costs
-350,000
Exemption
-0
Taxable gain
150,000
Tax (20.0%)
-30,000
Net gain after tax
120,000
Estimates only — not financial, tax, or professional advice.
100% private — every number you enter is calculated in your browser and never sent to our servers.
What it calculates: Estimated Capital Gains Tax, Capital Gain, Net Gain After Tax, Taxable Gain.
Updated 5 June 2026 · Transparent assumptions
$50,000 of improvements and selling costs are part of what the property cost you
Selling at $500,000 a property bought at $300,000 looks like a $200,000 gain. It is not. Capital improvements of $20,000 add to the cost basis, and $30,000 of selling costs — agent commission, legal fees, transfer taxes — reduce the proceeds. The taxable gain is $150,000, and at 20% the tax is $30,000 rather than $40,000.
That $10,000 difference is the single most valuable thing most sellers can do about property capital gains, and it depends entirely on record-keeping. Receipts for improvements made years or decades earlier are what substantiate the basis, and without them the deduction is difficult to claim.
Capital improvements add to basis; repairs and maintenance do not
The distinction is whether the work adds value, prolongs the property\u2019s life or adapts it to a new use. A new roof, an extension, a rewire, a replacement kitchen and landscaping generally qualify. Repainting, fixing a leak, replacing a broken window and routine maintenance generally do not — they preserve the property rather than improve it.
For a rental property there is a further complication in the other direction: depreciation claimed while letting reduces the basis, so a landlord who deducted depreciation for years faces a larger gain on sale, and in several systems that portion is taxed at its own rate. Improvements raise the basis; depreciation lowers it, and both must be tracked.
A main-residence exemption can eliminate the tax entirely
Most systems treat a principal residence far more favourably than an investment property. The US excludes up to $250,000 of gain for a single filer and $500,000 for a married couple filing jointly, subject to ownership and use tests; the UK gives full private residence relief for a property occupied throughout ownership. Either can reduce the taxable gain here to zero.
The conditions are specific and worth checking before relying on them: minimum periods of ownership and occupation, restrictions on how often the relief can be claimed, and apportionment where the property was let or used for business during part of the period. Entering an exemption you do not actually qualify for is the easiest way to understate this liability badly.
Holding period, bands, depreciation recapture and jurisdiction
The rate applied here is flat. Real capital gains rates usually depend on how long the property was held, on total income for the year, and in several systems on whether the gain is indexed for inflation. Depreciation recapture on a former rental is frequently taxed at a different and higher rate than the rest of the gain.
State, provincial or local taxes stack on top, and some jurisdictions apply an additional surcharge on investment income above a threshold. Deferral mechanisms — like-kind exchanges, rollover relief and instalment sales — can change the timing entirely. For a sale of any size, this is a first estimate and a professional calculation is warranted.
Sources & References
Figures on this page are checked against primary, authoritative sources. Links open in a new tab.
Tax rules vary by country, state, tax year, filing status, income type, deductions, and exemptions. This calculator is educational and uses the values you enter. Always verify final tax treatment with official sources or a qualified tax professional.
Published the calculator with its formula, worked example, assumptions, limitations and a bespoke guide, and added an automated formula test suite covering it.
Verified that improvements raise the cost basis and selling costs reduce the proceeds, so both lower the taxable gain — the deduction most sellers miss.
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