Capital Gains Tax ATO Calculator
Estimate your Australian capital gain, CGT discount, taxable capital gain, and indicative tax impact using a premium calculator designed around common ATO rules for individuals, trusts, companies, and super funds.
Calculate your capital gains tax estimate
Enter your asset details below. This tool is designed for Australian tax residents and provides an informed estimate only. It is especially useful when planning for property, shares, crypto, and investment asset disposals.
Your estimated result
The result panel breaks down your gross gain, cost base, discount, taxable capital gain, and estimated tax impact.
How to use a capital gains tax ATO calculator effectively
A capital gains tax ATO calculator helps Australian taxpayers estimate the tax impact of selling an asset such as an investment property, parcel of shares, exchange traded fund, crypto holding, or business asset. While no online tool can replace formal tax advice, a good calculator can provide a very useful planning estimate before you sell, reinvest, or set aside cash for your annual tax bill.
In Australia, capital gains tax is not usually a separate tax rate by itself. Instead, your net capital gain is generally included in your assessable income for the financial year. That means the final tax cost depends on your total taxable income, your entity type, whether you can apply current year or prior year capital losses, and whether you are eligible for the CGT discount. The calculator above is designed to reflect these practical ATO concepts in a simple format.
One of the biggest mistakes investors make is focusing only on the profit between purchase and sale price. The ATO framework is broader. The cost base of an asset can include acquisition costs, ownership related capital costs in some situations, and improvement costs. Disposal costs also matter. As a result, an accurate capital gains estimate starts with better record keeping, not just a rough purchase and sale comparison.
What this calculator includes
- Purchase price and sale price of the asset.
- Buying costs such as stamp duty, legal fees, and brokerage where applicable.
- Selling costs such as agent commission, legal fees, and platform costs.
- Capital improvement costs that may form part of the cost base.
- Capital losses applied before any CGT discount.
- Holding period to test general discount eligibility.
- Taxpayer type, because individuals, trusts, companies, and super funds do not all receive the same treatment.
- Other taxable income for estimating the marginal tax impact of the gain.
What is capital gains tax in Australia
Capital gains tax applies when a CGT event happens, usually when you dispose of a CGT asset. The most common CGT event is selling an asset, but there are other events too, such as gifting an asset in some circumstances, changing beneficial ownership, or receiving certain insurance or compensation payments. The gain is generally calculated as capital proceeds minus the asset’s cost base.
For many Australian taxpayers, the basic sequence works like this:
- Work out your capital proceeds from the disposal.
- Work out your cost base, including eligible purchase, improvement, and disposal costs.
- Calculate your capital gain or capital loss.
- Offset any capital losses against capital gains.
- Apply any available CGT discount if the asset qualifies.
- Include the resulting net capital gain in taxable income.
This calculator follows that broad approach. It estimates the cost base, applies capital losses first, checks whether the holding period exceeds 12 months, and then applies the relevant discount where appropriate.
Who can use the CGT discount
The CGT discount is one of the most valuable features of the Australian tax system for long term investors. In general terms, individuals and trusts can reduce an eligible capital gain by 50% if the asset was held for at least 12 months before the CGT event. Complying super funds generally receive a one third discount. Companies do not receive the CGT discount.
That difference materially changes planning outcomes. If two taxpayers realise the same gross capital gain, the one eligible for a discount may pay substantially less tax than a company or short term trader. That is why the calculator asks for your entity type and holding period.
| Taxpayer type | General CGT discount position | Typical planning implication |
|---|---|---|
| Individual | 50% discount may apply if held more than 12 months | Long term investors often have a lower taxable gain than short term sellers |
| Trust | 50% discount may apply at trust level before distribution, subject to rules | Beneficiary outcomes depend on trust structure and distributions |
| Complying super fund | One third discount may apply if held more than 12 months | Effective tax on discounted gain can be significantly lower than personal rates |
| Company | No general CGT discount | Full capital gain is usually taxed at the relevant company rate |
Australian resident income tax rates used for estimation
For individuals and trusts, the calculator estimates tax using Australian resident marginal rates and a 2% Medicare levy estimate. It does not attempt to model every tax offset, surcharge, non resident rule, family trust rule, or special concession. The aim is to provide a realistic directional estimate for common scenarios.
| Taxable income band | Resident rate used | Indicative note |
|---|---|---|
| $0 to $18,200 | 0% | No income tax in this band, though other rules can still matter in practice |
| $18,201 to $45,000 | 16% | Lower middle income marginal band |
| $45,001 to $135,000 | 30% | Broad band that captures many salary earners and investors |
| $135,001 to $190,000 | 37% | Higher marginal band before the top rate threshold |
| Over $190,000 | 45% | Top marginal rate, before Medicare levy and any specific surcharges |
Worked example using the calculator
Suppose you bought an investment property for $500,000. You paid $25,000 in acquisition costs, later spent $15,000 on capital improvements, and then sold the property for $720,000 while paying $18,000 in selling costs. Assume you held the property for 24 months, had no carried forward capital losses, and your other taxable income for the year is $90,000.
Your estimated cost base would be $540,000, made up of the purchase price plus buying costs plus capital improvements. If the sale price is $720,000, the gross capital gain before sale costs would look large, but for an estimate like this we account for selling costs too, resulting in a net capital gain of $162,000 before any CGT discount. Because the asset was held for more than 12 months and the owner is assumed to be an individual, a 50% discount may apply. That reduces the taxable capital gain to $81,000. This taxable gain is then added to other taxable income to estimate the marginal tax effect.
This is exactly where a calculator becomes helpful. A seller often sees a headline profit and assumes that amount is taxable. In reality, the taxable amount could be meaningfully lower after properly including transaction costs and any discount entitlement. On the other hand, if the seller is a company, no general discount is available, which can materially increase the estimated tax impact.
Common mistakes when estimating CGT
- Ignoring buying and selling costs that are part of the cost base.
- Confusing repairs with capital improvements.
- Applying the CGT discount before capital losses.
- Assuming companies receive the same discount as individuals.
- Forgetting that the gain is usually added to other taxable income.
- Using a calculator for a main residence scenario without checking exemptions and partial exemption rules.
- Not considering records for inherited assets, gifted assets, or assets acquired before major rule changes.
Property, shares, and crypto, why asset type still matters
Although the basic CGT formula is similar across many asset classes, practical record keeping differs a lot by asset type. Property investors often need to distinguish capital improvements from deductible repairs, and they need accurate records for legal fees, buyer’s agent costs, stamp duty, and selling commission. Share investors often need to account for brokerage and parcel level purchase history. Crypto investors can face even greater complexity because they may have many transactions across multiple wallets and exchanges, and each disposal can trigger a CGT event.
The calculator lets you choose an asset type because that helps frame your estimate, even though the underlying arithmetic remains centered on cost base, proceeds, losses, and discount eligibility. If your history is complex, especially with crypto or corporate actions affecting shares, you should confirm the figures against transaction level records before relying on the estimate.
How capital losses affect the result
Capital losses are valuable because they can be used to offset capital gains. In broad terms, losses are applied before the CGT discount. This order matters. If you have a gain of $100,000 and capital losses of $20,000, you generally apply the $20,000 loss first, reducing the gain to $80,000. If the remaining gain is discount eligible and you are an individual, the 50% discount may then reduce the taxable capital gain to $40,000.
That treatment is one reason why accurate historic records are so important. Carried forward losses can materially reduce the tax cost of a sale. Investors who have sold shares, property interests, or crypto at a loss in earlier periods should ensure those losses are correctly documented and available for offset where the law permits.
Why timing a sale can change your tax outcome
The timing of disposal can influence your tax bill in two major ways. First, waiting until you have held an eligible asset for at least 12 months may open access to the CGT discount. Second, selling in a year where your other taxable income is lower could reduce the marginal tax rate applying to the gain. For many Australians, those two levers can produce a significant difference in after tax proceeds.
This is why a capital gains tax ATO calculator is useful not only after a sale but before it. You can model multiple scenarios, such as selling before or after the 12 month mark, or deferring the sale into a different financial year. The chart in this calculator also helps you visualise how much of the profit is retained after losses, discount treatment, and estimated tax.
Official sources and further reading
If you need authoritative guidance, review the Australian Taxation Office material on capital gains tax and tax rates. You may also find university resources helpful for understanding tax law concepts at a deeper level. Start with these sources:
- ATO, Capital gains tax overview
- ATO, Tax rates and codes
- UNSW, university level legal and taxation study resources
When to seek professional advice
A calculator is ideal for planning, but there are many situations where professional advice is worth the cost. These include partial main residence exemptions, inherited assets, divorce or relationship breakdown transfers, small business CGT concessions, non resident tax issues, trust streaming, demergers, rights issues, share buy backs, employee share schemes, and crypto transactions with staking or complex on chain activity. In those cases, a registered tax agent or qualified adviser can verify your exact treatment and help you avoid underpaying or overpaying tax.
For most standard investment disposals, though, a quality capital gains tax ATO calculator remains an excellent first step. It helps you understand how cost base items, losses, holding period, and tax rates interact, and it gives you a practical estimate of how much tax may arise from a sale.