Capital gains tax calculator: what the sale actually costs.
CGT is not a separate tax - the gain is added to your income and taxed at your marginal rates, so what else you earn that year decides the bill. This works it out properly: the full cost base, carried-forward losses applied before the discount rather than after, and the tax measured as the difference the gain makes to your return.
What you sold it for
What it cost you
The cost base, not just the price. Leaving these out is the most expensive mistake on a property sale.
Your situation
Capital gains tax you'd pay
$61,500
On a $290,000 gain, added to $120,000 of other income. That is an effective 21.2% of the gain, leaving you $228,500.
The CGT event is the contract date
Not settlement. A contract signed on 28 June puts the whole gain in that financial year even if the money arrives in August - which is why the timing of a sale, and what else you earn that year, moves the bill more than almost anything else. Selling in a year you take leave without pay, or after retiring, is a different number entirely.
Rates as at 1 July 2026, for an Australian resident individual. Capital gains tax is not a separate tax: the net gain is added to your taxable income for the year and taxed at marginal rates plus the Medicare levy, which is how this is worked out. Carried-forward losses are applied BEFORE the 50% discount, which is the required order. It assumes the asset is not your main residence - the main residence exemption, the six-year absence rule, partial exemptions, pre-1985 assets, depreciation and building write-back adjustments, small business CGT concessions, assets held in a trust, company or SMSF, and foreign resident rules are all outside it, and any one of them can change the answer completely. Nothing you type is stored or sent. General information only, not tax or personal financial advice - talk to your accountant before you sign a contract.
Three things most CGT calculators get wrong.
The cost base is not the purchase price. Stamp duty, legal fees, inspections, loan establishment costs and every capital improvement go into it. On a property bought for $520,000, the buying costs and a renovation can easily add $70,000 to the base - which at a 45% marginal rate is around $15,000 of tax you would otherwise have paid for no reason. Repairs do not count; they were deductible against rent at the time.
Losses come off before the discount. Deduct your capital losses from the gross gain first, then halve what remains. Discounting first and subtracting losses afterwards inflates the discount and understates the tax - a surprisingly common error, and one that produces a number you will have to explain later.
The rate is yours, not a flat number. Because the net gain is added to your income, a large gain pushes part of itself into higher brackets. Multiplying the discounted gain by a single tax rate gets it wrong in both directions depending on where you sit. This calculator takes the difference between your tax with the gain and without it, which is what the ATO does.
The lever that follows from all three is timing. The CGT event is the contract date, so a sale can be pushed into a year where your income is lower, where a deductible super contribution is available, or where a carried-forward loss is waiting. If the proceeds are heading into retirement, the superannuation calculator and property investment advice are the next questions.
Capital gains tax
Frequently asked questions.
How is capital gains tax calculated in Australia?
There is no separate CGT rate. You work out the gain (what you sold it for, less selling costs, less the cost base), take the 50% discount if you owned it more than 12 months, then add what is left to your taxable income for the year and pay tax at your marginal rates plus the Medicare levy. That is why the same gain costs two people very different amounts, and why the year you sell in matters as much as the gain itself.
What goes into the cost base?
More than the purchase price, and this is where most money is lost. Stamp duty, conveyancing and legal fees, building and pest inspections, buyer's agent fees and loan establishment costs all count, as do capital improvements such as a renovation or an extension. Repairs and maintenance do not - those are deductible against rent instead. Keep the receipts: the ATO expects you to substantiate the cost base, and a forgotten $40,000 renovation is roughly $9,000 of unnecessary tax at a 45% marginal rate.
Do I get the 50% discount?
If you are an individual and you held the asset for MORE than 12 months, yes. The clock runs from the day after you acquired it to the contract date of the sale, not settlement, so a sale at eleven and a half months costs you half the discount for the sake of a fortnight. SMSFs get a third rather than a half; companies get no discount at all.
In what order do losses and the discount apply?
Losses first, then the discount. Deduct your capital losses (this year's and any carried forward) from the gross gain, and apply the 50% discount to what remains. Doing it the other way round - discounting first and then subtracting losses - overstates the discount and understates the tax, and it is a common error in both spreadsheets and online calculators.
What if I sell at a loss?
A capital loss cannot be offset against your salary or other income. It can only reduce capital gains - this year's, or any year's after that, since it carries forward indefinitely until used. That makes an unused loss a genuine asset worth tracking, and worth considering when timing a later sale.
Is my home exempt?
Your main residence is generally exempt, and this calculator assumes the asset is not one. The rules around it are where the complexity lives: the six-year absence rule if you move out and rent it, partial exemptions where a property was your home for only part of the time or was used to produce income, and the market-value substitution when a home first becomes an investment. Any one of those changes the answer completely, so get advice before you sign.
Can I reduce the bill?
Timing is the biggest lever and the one people leave until too late: the CGT event is the contract date, so a sale straddling 30 June lands the whole gain in one year or the other, and a year with lower income means a lower marginal rate. Beyond that, holding past 12 months for the discount, making a deductible concessional super contribution in the same year, realising an unused capital loss, and how the asset is owned all move the number. Every one of them has to be decided before you sign, not after.
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The bill is decided before you sign, not after.
Timing, ownership, the cost base and what else you earn that year all move a capital gains bill - and every one of them has to be decided before the contract date. Worth a conversation first.
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