ATO CGT Calculator
Estimate your Australian capital gains tax outcome with an easy, premium calculator designed for individuals, trusts, companies, and complying super funds. Enter your sale details, cost base, ownership period, losses, and taxable income to see a practical CGT estimate based on common ATO rules and discount treatment.
Calculate your capital gains tax estimate
This calculator assumes you are an Australian tax resident and that the asset is not fully exempt, such as a qualifying main residence. It provides an estimate only and should be checked against current ATO guidance.
Estimated result
Your calculation updates when you click the button. The chart compares proceeds, cost base, gains, losses, discount, and estimated tax.
Important: This estimate excludes Medicare levy, small business concessions, rollover relief, partial exemptions, foreign resident rules, indexation for pre 21 September 1999 assets, and many asset specific adjustments.
How to use an ATO CGT calculator effectively
An ATO CGT calculator helps you estimate the tax impact of selling an investment asset such as shares, cryptocurrency, managed funds, business assets, or an investment property. CGT stands for capital gains tax, but in Australia it is not a separate tax. Instead, your net capital gain is usually added to your assessable income and taxed at your marginal rate if you are an individual or according to the relevant entity tax rate if you are a company or complying super fund.
The practical challenge for taxpayers is that capital gains are rarely just the difference between purchase price and sale price. You must usually consider the asset cost base, any eligible purchase and selling costs, certain capital improvements, prior year capital losses, the ownership period, and whether a CGT discount is available. That is exactly why a well built calculator is useful. It does the arithmetic quickly and gives you a more realistic estimate before you lodge your tax return or speak with an accountant.
This page is designed as a premium educational calculator for Australian users. It mirrors the common ATO sequence used in many cases: work out your capital proceeds, subtract the cost base, apply capital losses, then apply any available discount. Finally, it estimates the tax effect. While it is not a substitute for professional advice, it can help you understand the likely outcome and prepare the right records for tax time.
What counts as a capital gain in Australia?
A capital gain generally arises when a CGT event happens and the capital proceeds from the asset are more than its cost base. The most common CGT event is the sale of an asset. Examples include:
- Selling an investment property that is not fully exempt under the main residence rules.
- Selling listed shares or exchange traded funds for more than your adjusted cost base.
- Disposing of cryptocurrency where the transaction is taxable.
- Selling business assets, goodwill, or units in a trust.
- Redeeming or disposing of certain managed fund investments.
Your cost base usually includes more than the purchase price. It can include acquisition costs such as stamp duty and legal fees, ownership related costs in some circumstances, and capital improvement costs that are not otherwise deductible. Disposal costs such as agent commissions and sale advertising are also commonly included. Because these amounts reduce your gain, accurate records can make a significant difference.
How this calculator estimates your capital gains tax
The calculator above follows a straightforward logic that aligns with common ATO treatment for many taxpayers:
- It adds your purchase price, acquisition costs, disposal costs, and capital improvements to determine an estimated cost base.
- It subtracts that cost base from the sale proceeds to determine a preliminary capital gain or capital loss.
- If there is a gain, it subtracts current year or carried forward capital losses.
- It then tests discount eligibility based on entity type and ownership period. Individuals and trusts can generally receive a 50% discount after holding the asset for at least 12 months. Complying super funds can generally receive a one third discount. Companies generally do not receive the discount.
- It estimates the tax impact. For individuals and trusts, it calculates the additional tax that would result from adding the net capital gain to your other taxable income using resident tax rates. For companies and complying super funds, it applies common flat rates.
This approach creates a useful estimate for planning purposes. However, some assets and situations require more detailed analysis, including depreciating assets, foreign residents, partial main residence exemptions, deceased estates, marriage breakdown rollovers, and small business CGT concessions.
Key ATO concepts you should understand
If you want a reliable CGT estimate, these concepts matter most:
- Capital proceeds: what you received or are taken to have received when the CGT event happened.
- Cost base: your purchase price plus eligible incidental costs and some capital costs.
- Reduced cost base: often relevant when calculating a capital loss.
- Capital losses: these can offset capital gains, but generally cannot be deducted against salary or ordinary income.
- CGT discount: often 50% for individuals and trusts, one third for complying super funds, and not available to companies.
- Net capital gain: the amount that ultimately flows into your tax calculation.
2024 to 2025 resident individual income tax rates used for estimating extra tax
For individuals and many trusts, the most useful way to estimate CGT is to work out the extra tax generated when the net capital gain is added to other taxable income. The table below shows the resident income tax brackets commonly used for 2024 to 2025 calculations, excluding the Medicare levy. This allows the calculator to approximate your incremental tax rather than just multiplying the gain by a single rate.
| Taxable income | Marginal treatment | Common use in CGT estimate |
|---|---|---|
| $0 to $18,200 | Nil | No income tax on this band |
| $18,201 to $45,000 | 16% | Part of your discounted gain may fall here |
| $45,001 to $135,000 | 30% | Many investment property gains land in this band |
| $135,001 to $190,000 | 37% | Higher earners may have a larger incremental CGT impact |
| Over $190,000 | 45% | Top marginal rate for the excess amount |
Because CGT is layered onto your ordinary income, the same capital gain can produce very different tax outcomes for two people. Someone with taxable income of $50,000 may have much of their discounted gain taxed at 30%, while someone already above $190,000 may see much of the gain taxed at 45%. That is why entering your taxable income before the sale is important.
Discount rules by entity type
Entity type is one of the most important variables in any ATO CGT calculator. The discount available can materially change the result. The following table summarizes the common treatment for Australian residents where the asset has been held for at least 12 months and no special exclusion applies.
| Entity type | Common CGT discount treatment | Illustrative tax approach in calculator |
|---|---|---|
| Individual | 50% discount usually available after 12 months | Extra tax estimated using resident tax brackets |
| Trust | 50% discount may flow through subject to beneficiary taxation outcomes | Estimated using resident tax brackets for a planning level result |
| Company | No general CGT discount | Estimated at a 30% flat rate in this tool |
| Complying super fund | One third discount after 12 months | Estimated at 15% tax, effectively 10% on discounted gains |
Example of a typical CGT calculation
Assume you sell an investment property for $850,000. You originally paid $600,000. Eligible acquisition costs were $18,000, disposal costs were $22,000, and capital improvements were $30,000. Your total cost base is therefore $670,000. Your preliminary capital gain is $180,000. If you have $10,000 in capital losses, that reduces the gain to $170,000. If you are an individual and owned the property for more than 12 months, the 50% discount may reduce the taxable gain to $85,000. That $85,000 is then added to your other taxable income to estimate the additional tax payable.
This is why record keeping matters. If you forget to include a legitimate improvement or sale cost, your taxable gain could look much larger than it really is. Likewise, failing to apply available capital losses before the discount can create an incorrect estimate. The order of the steps matters.
Common mistakes people make when using an ATO CGT calculator
- Ignoring incidental costs: legal fees, stamp duty, and selling commissions can materially reduce your gain.
- Using repairs as improvements: ordinary repairs may not form part of the cost base in the same way capital improvements do.
- Applying the discount too early: capital losses are generally applied before the CGT discount.
- Assuming every asset gets the discount: companies generally do not qualify, and some assets have special rules.
- Forgetting partial exemptions: for example, a property may have mixed private and investment use, changing the outcome.
- Not considering timing: the gain is generally recognized in the income year when the contract is entered into, not necessarily settlement date in all property transactions.
When this calculator is especially useful
A planning calculator is valuable when you are deciding whether to sell before or after 12 months, whether to realize losses in the same year, or whether to defer a disposal into a different tax year. It is also useful if you are comparing personal ownership with company or super fund ownership for future investments. While ownership structure decisions should never be made on tax alone, CGT treatment can be a major factor.
For investors, even a rough estimate can improve cash flow planning. Selling an appreciated share portfolio or investment property without anticipating the tax effect can create an unpleasant surprise. A calculator helps you reserve enough funds for the likely liability and avoid overcommitting sale proceeds.
What this tool does not cover
No online calculator can replace a tailored tax review in complex cases. This tool does not model every concession or exception. For example, it does not calculate:
- Main residence partial exemptions or the absence rule.
- Small business 15 year exemption, 50% active asset reduction, retirement exemption, or rollover.
- Foreign resident withholding or foreign resident CGT restrictions.
- Indexation for assets acquired before 21 September 1999.
- Detailed trust streaming outcomes or beneficiary specific tax profiles.
- Collectables and personal use asset threshold rules.
- Crypto transaction lot matching or chain specific cost base reconstruction.
Those issues may substantially change your result. If your transaction is large, unusual, or involves mixed use, it is wise to seek professional advice.
Authoritative sources for CGT rules
If you want to validate your numbers or understand a rule in detail, start with official Australian guidance. Useful resources include the Australian Taxation Office, the ATO material on capital gains tax for individuals and families, and broader legislative context published by the Australian Government Treasury. For property and investor market context, many users also review economic data from the Australian Bureau of Statistics.
Best practice before you lodge your tax return
- Gather the contract of purchase and contract of sale.
- Collect legal invoices, stamp duty statements, and selling agent invoices.
- Identify capital improvements separately from repairs and maintenance.
- Check for any prior year capital losses available to offset gains.
- Confirm your ownership dates and whether the 12 month discount rule is satisfied.
- Review whether any exemption, rollover, or concession may apply.
- Compare your estimate with official ATO instructions or speak with a registered tax adviser.
Final thoughts on using an ATO CGT calculator
An ATO CGT calculator is most powerful when it is used as a decision support tool rather than a final tax answer. It can help you estimate the effect of selling now versus later, understand the value of the 12 month discount period, and appreciate how capital losses can reduce tax. Most importantly, it encourages better record keeping and more informed planning.
The calculator on this page is intentionally practical. It captures the major moving parts that most taxpayers need: capital proceeds, cost base, losses, ownership period, taxpayer type, and taxable income. With those inputs, you can build a much clearer picture of your likely CGT position and know when it is time to seek expert advice.