Australian CGT Calculator
Use this estimator for shares, investment property, crypto, and other taxable assets. It calculates an estimated taxable capital gain and estimated tax based on your marginal rate.
How capital gains tax works in Australia
Capital gains tax (CGT) is not a separate tax. It is part of your income tax. When you sell a CGT asset for more than its cost base, the gain is included in your taxable income for the financial year. Common CGT assets include investment properties, shares, managed funds, ETFs, business assets, and crypto.
For most people, the core formula is simple:
- Capital proceeds (what you sold for)
- minus Cost base (purchase price + eligible costs)
- minus capital losses (current year or carried forward)
- minus CGT discount (if eligible)
- equals taxable capital gain.
What this CGT calculator includes
This calculator is designed for fast planning. It estimates your gain, applies available losses, checks if the 12-month discount may apply, and then estimates tax using your entered marginal tax rate and Medicare levy.
Included in the estimate
- Purchase and sale values
- Buying/selling costs
- Capital improvement costs
- Capital losses
- Discount method for eligible taxpayers
Not fully modelled
- Partial main residence exemptions
- Small business CGT concessions
- Pre-CGT assets (acquired before 20 September 1985)
- Complex trust/company distributions
- Indexation method for older assets
Step-by-step: using the calculator correctly
1) Enter your true cost base
Many people underestimate CGT because they only enter the purchase price. In Australia, your cost base can also include stamp duty, legal fees, buyer’s agent costs, selling agent fees, and eligible non-deducted capital improvements.
2) Add capital losses
Capital losses reduce capital gains, but they do not reduce salary or other ordinary income. If losses exceed gains, the unused balance usually carries forward to future years.
3) Check the 12-month rule
The discount generally applies only if the asset was held for at least 12 months. Individuals and trusts may receive a 50% discount, while complying super funds may receive a 33.33% discount. Companies generally do not receive this discount.
4) Use your own tax rate
CGT is taxed at your marginal rate after adjustments. Entering your realistic marginal rate gives a more useful estimate for budgeting and cash flow.
Example calculation (investment property)
Suppose you bought an investment property and later sold it with the following figures:
- Purchase price: $500,000
- Buying costs: $22,000
- Improvements: $30,000
- Selling costs: $18,000
- Sale price: $760,000
- Capital losses carried forward: $10,000
Your cost base is $570,000. Gross gain is $190,000. After losses, gain is $180,000. If eligible for the 50% discount, taxable capital gain becomes $90,000. That amount is then taxed at your marginal tax rate (plus levy where relevant).
Common CGT mistakes to avoid
- Ignoring transaction costs: legal, brokerage, and agent fees can materially reduce gain.
- Forgetting carried-forward losses: these can significantly lower tax.
- Confusing revenue repairs with capital improvements: they are treated differently.
- Assuming your home is always fully exempt: it may be partial in mixed-use/rental periods.
- Not keeping records: missing documents often leads to overstated tax.
Record-keeping checklist for CGT in Australia
Keep records for at least five years after the relevant tax return (often longer if needed to support cost base). Useful documents include:
- Contract of purchase and contract of sale
- Settlement statements
- Stamp duty and legal invoices
- Agent commission and advertising costs
- Invoices for capital improvements
- Corporate action statements (for shares/funds)
- Crypto wallet and exchange transaction exports
FAQ: cgt calculator australia
Does this calculator replace tax advice?
No. It provides a planning estimate only. Tax outcomes can change based on your exact facts, timing, and ATO rules.
Can I use this for shares and ETFs?
Yes. Enter your buy/sell amounts, brokerage, and any capital losses. For parcels purchased at different times, you may need separate calculations.
What if I made a capital loss?
If your result is negative, you generally have a net capital loss. This cannot usually reduce salary income, but may be carried forward to offset future capital gains.
Is the main residence always exempt?
Not always. Full exemption commonly applies to an owner-occupied home, but partial CGT can apply if it was rented, used for income, or not your main residence for the full ownership period.