Capital Gains Tax Calculator Australia (2025–26)

Understanding Capital Gains Tax in Australia

Capital Gains Tax (CGT) is one of the most significant tax considerations for Australian investors. Whether you are selling an investment property in Sydney, offloading a parcel of shares, or disposing of a business asset, understanding how CGT works — and how to legitimately minimise it — can save you thousands of dollars.

This guide covers the key rules that apply to individual Australian taxpayers (not companies or self-managed super funds, which have different rules). Always consult a registered tax agent or accountant for advice specific to your situation.

The 50% CGT Discount: Australia's Most Valuable Tax Break for Investors

The single most important CGT rule for long-term investors is the 50% discount. If you are an individual or trust and you hold a capital asset for more than 12 months before selling it, you only include 50% of the net capital gain in your assessable income. The other 50% is permanently excluded — you never pay tax on it.

To illustrate: suppose you bought an investment property for $600,000 (including acquisition costs) and sell it five years later for $900,000 (net of disposal costs). Your gross capital gain is $300,000. Because you held it for more than 12 months, you apply the 50% discount: only $150,000 is added to your taxable income. At the 32.5% marginal rate, your CGT liability is $48,750 — a saving of $48,750 compared with selling before the 12-month mark.

This is why experienced property and share investors plan their sale timing carefully around the 12-month threshold.

What Goes Into the Cost Base?

Your cost base determines your capital gain: a higher cost base means a smaller gain and less tax. Many investors pay more CGT than necessary because they forget to include all allowable costs. The five elements of the cost base under Australian tax law are:

• Purchase price — the amount you paid for the asset.
• Incidental costs of acquisition — stamp duty, conveyancing fees, legal fees, building and pest inspections, buyer's agent fees, and valuation costs paid when buying.
• Non-deductible ownership costs — for investment properties, costs like interest, rates, insurance, and repairs are deductible and cannot be added to the cost base. But if you use the property partly for private purposes (or it's vacant land), some costs may be non-deductible and therefore can be added.
• Capital expenditure — money spent to add to or improve the value of the asset (e.g. adding a bedroom, renovating a kitchen) rather than maintaining it. Repairs and maintenance are deductible expenses, not capital.
• Incidental costs of disposal — agent's commission, advertising, conveyancing fees, and legal costs paid when selling. These reduce your capital proceeds rather than increasing your cost base, but the net effect on your CGT calculation is the same.

CGT on Investment Property

Investment properties are the most common CGT asset for Australian investors. Key points to understand:

• No main residence exemption — if the property was never your primary place of residence, there is no exemption. The full capital gain (less the 50% discount if held >12 months) is taxable.
• Partial main residence exemption — if you lived in the property for part of your ownership period and rented it for part, you can apportion the gain. The formula is based on the number of days it was your main residence divided by the total days of ownership.
• The 6-year rule — if you move out of your home and rent it, you can continue to treat it as your main residence for up to 6 years (the "absence rule"). No CGT will apply to any gain arising during those 6 years, provided you don't treat another property as your main residence simultaneously.
• Depreciation recapture — if you have claimed building depreciation (Division 43) on the property, the ATO may add back those amounts to reduce your cost base, increasing your capital gain. Your accountant should calculate this.

CGT on Shares and ETFs

The same CGT rules apply to Australian and international shares, managed funds, and ETFs. A few nuances:

• Parcel tracking — if you own multiple parcels of the same share (bought at different times and prices), you can choose which parcel to sell. Selling higher-cost parcels first minimises your CGT.
• Dividend reinvestment plans — each set of shares acquired through a DRP has its own purchase date and cost base equal to the market value on the date of reinvestment. The 12-month clock starts from that DRP acquisition date.
• Wash sales — the ATO has specific rules against "wash sale" arrangements where you sell a loss-making parcel to crystallise the loss, then immediately repurchase it. The ATO can treat such arrangements as tax avoidance.
• AMIT and ETF distributions — some ETFs pass through capital gains as attributed managed investment trust (AMIT) distributions. These may already have the 50% discount applied by the fund, which is reflected in your annual tax statement.

CGT Strategies for Australian Investors

While the calculator gives you an estimate, there are legitimate strategies that can reduce your CGT:

• Hold for 12 months — the simplest and most powerful. If you are close to the 12-month threshold, waiting a few weeks can halve your tax bill.
• Time the sale for a low-income year — capital gains are taxed at your marginal rate. If you know you will be on a lower income next year (career break, retirement, parental leave), selling in that year can significantly reduce your CGT.
• Offset with capital losses — if you have unrealised losses in other investments, you might crystallise those losses to offset the gain. Be careful of wash sale rules.
• Superannuation — selling assets inside superannuation is taxed at 10% (not your marginal rate), and 15% on assets held less than 12 months. Assets held until retirement and sold in pension phase are generally tax-free.
• Maximise the cost base — ensure all allowable costs are included. Keep receipts for every capital improvement over the ownership period.

When to See a Tax Accountant

This calculator provides an estimate for educational purposes. It does not account for: the Medicare levy surcharge; main residence exemptions and apportionments; depreciation recapture on rental properties; foreign resident CGT withholding; small business CGT concessions; or complex trust and company structures. For any significant asset sale, the fee for professional tax advice is almost certainly worth it.