Australian Capital Gains Tax Calculator
Work out capital gains tax on an Australian asset sale for 2026-27, including the 50% discount for assets held over twelve months and the effect on your marginal rate.
How to use this calculator
- 1Enter the sale price and the full cost base — purchase price plus stamp duty, legal fees, agent commission and any capital improvements.
- 2Enter your other taxable income, since the gain stacks on top and may push part of it into a higher bracket.
- 3Confirm whether the asset was held more than twelve months from the day after acquisition to the contract date.
- 4Add any carried-forward capital losses, which are applied before the discount.
How the calculation works
Gain = sale price − cost base. Apply capital losses, then halve if held over 12 months. Tax = marginal rate on the remainder- cost base
- Purchase price plus acquisition and disposal costs and capital improvements
- 50% discount
- Halves the gain for individuals who held the asset more than twelve months
Australia has no separate CGT rate. The gain is added to assessable income and taxed at ordinary marginal rates, so the effective rate depends entirely on the taxpayer's bracket and on how much of the gain pushes them into a higher one.
Capital losses are applied to the gross gain before the discount. Applying the discount first would produce a smaller taxable figure and is wrong — the statutory order matters and this follows it.
The twelve months runs from the day after acquisition to the contract date of sale, not settlement. It is a cliff: one day short means the whole discount is lost, which can be worth tens of thousands.
Worked example
A $300,000 gain held over twelve months
- 1.Gross gain: $800,000 − $500,000 = $300,000.
- 2.The 50% discount halves it to $150,000 of taxable gain.
- 3.That $150,000 stacks on $95,000 of income, pushing well into the 37% and 45% brackets.
- 4.The resulting tax is well below 45% of the full gain, because only half of it is taxable.
Result: Roughly a fifth of the gross gain, thanks to the discount
The same sale one day too early
- 1.Without the discount the full $300,000 is taxable.
- 2.It stacks on $95,000 of income and much of it reaches the top 45% bracket.
- 3.The tax roughly doubles compared with holding past the twelve-month mark.
- 4.The difference is decided by the contract date, not the settlement date.
Result: Roughly double the tax — the cliff in action
A discount, not a rate
Many countries tax capital gains at a dedicated, lower rate. Australia does not. A net capital gain is simply added to assessable income and taxed at whatever marginal rates it reaches, alongside salary.
The relief takes a different form: an individual who has held an asset for more than twelve months excludes half the gain from tax altogether. The rate is unchanged; the taxable amount is halved. For someone in the top bracket that produces an effective rate of about 23.5% on the full gain, since 45% plus the 2% levy applies to only half of it.
The practical consequence is that the same gain costs very different amounts to different people. A large gain also pushes the taxpayer up through brackets in the year of sale, so the marginal rate applied to the gain is often higher than the rate on their salary alone — which is why spreading disposals across tax years is such a common strategy.
Twelve months, and why the date matters so much
The discount is binary. Hold for more than twelve months and half the gain disappears; hold for one day less and none of it does. On a $300,000 gain for a high earner, that single day is worth tens of thousands of dollars.
Two details decide it. The clock starts the day *after* acquisition, not on the acquisition date — so a full calendar year is not quite enough. And the disposal date is the date of the contract, not settlement. For property in particular that distinction matters enormously, because settlement often falls weeks or months after exchange, and it is the earlier date that counts.
Anyone approaching the boundary should check both dates against the contract before agreeing to a sale. It is one of the few tax outcomes that can be improved simply by waiting a fortnight.
Cost base and losses: the two things people understate
The cost base is not just the purchase price. It includes stamp duty, conveyancing and legal fees, buyer's agent fees, and the selling costs at the other end — agent commission, marketing, legal. It also includes capital improvements: a renovation, an extension, a new roof. It does not include repairs and maintenance, or anything already claimed as a deduction.
For a property held two decades, documented improvements can add a six-figure sum to the cost base and reduce the gain accordingly. The records are worth keeping from the day of purchase, because reconstructing them later is difficult and the burden of proof sits with the taxpayer.
Capital losses work slightly differently from what most people expect. They are applied to the gross gain *before* the 50% discount, not after. Applying the discount first would leave a smaller taxable amount, and getting the order wrong in that direction understates the tax owed.
What this assumes, and where it stops
Assumptions
- An Australian resident individual, taxed at 2026-27 marginal rates.
- The asset is not a main residence, which would generally be exempt.
- Cost base is entered in full, including acquisition and disposal costs.
- Capital losses are applied before the discount, as the legislation requires.
Limitations
- The main residence exemption is not modelled and removes most home sales from CGT entirely.
- Small business CGT concessions, which can substantially reduce or eliminate a gain, are excluded.
- Assets acquired before 20 September 1985 are exempt and not handled here.
- Trusts, companies and superannuation funds are taxed differently — companies get no discount, and super funds get one third rather than one half.
Common questions
How much capital gains tax will I pay in Australia?
There is no separate rate — the gain is added to your income and taxed at your marginal rate. If you held the asset more than twelve months, only half the gain is taxable, which gives a top effective rate of about 23.5% on the full gain. A large gain will also push you into higher brackets in the year you sell, so the rate applied is often above the rate on your salary alone.
What is the 50% CGT discount and when do I get it?
It halves the taxable gain for individuals who held the asset more than twelve months. The clock runs from the day after acquisition to the *contract* date of sale, not settlement. It is a cliff rather than a taper — one day short and you lose all of it, which on a large gain can be worth tens of thousands. Companies get no discount and super funds get one third rather than one half.
What can I include in the cost base?
The purchase price plus stamp duty, legal and conveyancing fees, buyer's agent costs, and the costs of selling — agent commission, marketing and legal. Capital improvements count too: renovations, extensions, a new roof. Repairs, maintenance and anything already claimed as a tax deduction do not. On a long-held property, documented improvements can add a six-figure amount to the cost base.
Do capital losses come off before or after the discount?
Before. Losses are applied to the gross gain, and only what remains is halved. Applying the discount first would leave a smaller taxable amount, so getting the order wrong understates the tax owed. The statutory sequence is gross gain, then losses, then discount.
Sources
- CGT discount — Australian Taxation Office
- Calculating your CGT — Australian Taxation Office
Formula and content last reviewed on .
Results are estimates for information only, not professional advice.
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