Australian Capital Gains Tax Calculator

If you have recently sold an asset—like an investment property, shares, or cryptocurrency—and made a profit, you have triggered what the Australian Taxation Office (ATO) calls a CGT event.

But what exactly is Capital Gains Tax, and how does it affect your pocket?

Capital Gains Tax is Not a Separate Tax

One of the most common tax myths in Australia is that CGT is a standalone tax with its own flat rate. It is not.

Any net capital gain you make in a financial year is simply added directly onto your regular taxable income (like your salary or business earnings). The combined total is then taxed at your standard individual marginal tax rate.

• If you make a capital gain: The profit is added to your income, potentially pushing you into a higher tax bracket.
• If you make a capital loss: You cannot deduct a capital loss from your salary or wages. Instead, you must use it to offset capital gains made in the same year or roll the loss forward to offset future capital gains.

How a Capital Gain is Calculated

At its simplest, your capital gain is worked out using this basic formula:

If you bought an investment property for $500,000, paid $30,000 in buying and selling fees, and sold it for $650,000, your gross capital gain is:

The Landmark CGT Reforms (What You Need to Know)

Following the passage of the Treasury Laws Amendment (Tax Reform No. 1) Act 2026, Australia is undergoing its most significant CGT overhaul in over 25 years.

• Before 1 July 2027: The rules you see today apply. You can access the standard 50% discount if you hold an asset for more than 12 months.
• From 1 July 2027: The 50% discount will be replaced by a cost base indexation system (which adjusts your purchase price for inflation so you only pay tax on "real" gains) alongside a new 30% minimum tax rate on capital gains.

For over two decades, the "12-month rule" has been the most powerful tax-saving tool for Australian everyday investors. If you understand how this discount works—and how it is changing—you can save tens of thousands of dollars on your next tax return.

The Current 50% Discount Rule

Under current ATO rules, if you are an Australian resident individual (or investing through a trust) and you hold an asset for at least 12 months before signing the contract to sell it, you receive a 50% CGT discount. This means you only pay tax on half of your actual profit.

Example: You make a $100,000 net capital gain on some cryptocurrency. Because you held the coins for 14 months, the ATO applies the 50% discount. Your taxable capital gain is reduced to $50,000. If your marginal tax rate is 32.5%, you pay tax on $50,000 instead of the full $100,000—instantly saving you $16,250!

Warning: Major Changes are Now Law

The 2026 Federal Budget has officially passed legislation that changes the discount system forever starting 1 July 2027. Here is how the transition affects you:

The "New Build" Property Loophole

To encourage housing supply, the government has carved out a massive exception: if you invest in a new residential build, you retain the right to choose between the classic 50% discount or the new indexation method, even if you sell long after 1 July 2027.

💡 Investor Tip: Timing is everything. If you are planning to liquidate a heavily appreciated asset, consult with a professional to see if selling before the 1 July 2027 deadline makes financial sense for your situation.

The secret to legally minimizing your Capital Gains Tax is simple: maximize your cost base.

Your "cost base" is not just the sticker price you paid for your property, share portfolio, or crypto. It is the sum of all legal costs associated with owning, maintaining, and disposing of that asset. Every dollar you successfully add to your cost base is a dollar deducted from your taxable profit.

The ATO breaks the cost base down into five distinct, claimable elements:

1. The Money Paid for the Asset: This is the actual purchase price of the property, shares, or tokens.
2. Costs of Transferring and Acquiring the Asset: Stamp duty, solicitor/conveyancing fees, advertising costs to sell, real estate agent sales commissions, and valuation fees.
3. Costs of Owning the Asset (Property Specific): If you bought an investment property after 21 August 1991, you can include interest on the loan, council rates, land taxes, insurance premiums, and maintenance and repair costs that you did not already claim as annual deductions.
4. Capital Improvements and Renovations: Any money spent on permanent structural changes to increase or preserve the value of the asset. Keep every receipt as these capital improvements dramatically slash your taxable gain!
5. Costs to Defend or Establish Title: Any legal fees incurred to defend your ownership of the asset or establish your legal title over it.

The Depreciation Adjustment Trap: A Costly Trap for Landlords

If you own an investment property and have been claiming annual Capital Works Deductions (building depreciation) on your yearly tax returns, we have some vital news:

You must subtract those claimed depreciation amounts from your cost base when you sell.

This legally lowers your cost base, which inflates your net capital gain. Many investors are hit with surprise tax tax bills at settlement because they didn't factor this adjustment in.