Capital gains tax calculator Australia: the discount, Medicare levy and CPI indexation

A capital gain is what you receive minus your cost base, which includes brokerage on the way in and out. The gain belongs to the income year of the CGT event, and for a sale under contract that is the contract date, not settlement. If you owned the asset for at least 12 months, counting neither the day you bought it nor the day you sold it, and you are an Australian resident individual, the net gain is cut by 50% before it is added to your income.

The discounted gain is taxed at your marginal rate and carries the 2% Medicare levy with it. Crypto is a CGT asset like shares: selling it, swapping it for another coin and spending it are all disposals, each with its own cost base and holding period. Import your broker and exchange CSVs and the calculator matches the trades first in, first out and tests the holding period on every parcel.

A home that was your main residence for the whole time you owned it is exempt from capital gains tax. If it was your main residence for only part of the time, or you used part of it to earn income, only part of the gain is exempt. If you move out and rent the home, you can keep treating it as your main residence for up to six years.

Tick the main home box on the property card for a home you lived in throughout and the calculator treats the sale as exempt. A part-year exemption is worked out from your own records and is outside the calculator.

The cost base of an investment property is the price you paid plus stamp duty, legal fees and other costs of buying, plus capital improvements. Agent commission, advertising and legal fees on the sale come off the proceeds. The gain is then reduced by any capital losses, and the discount applies to what is left when you held the property for at least the minimum period.

Add the property to the calculator with its purchase costs, improvements and selling costs in their own fields. The contract date decides which income year the sale belongs to, so a contract signed in June and settled in August is a sale in the year that ends in June.

For a sale on or after 1 July 2027, indexation replaces the discount: your cost base is raised by the ABS consumer price index between purchase and sale, and there is no 50% reduction. An asset you hold on the day before is treated as sold and re-bought at its market value, so the gain up to that value keeps the discount and only the growth after it is indexed. A 30% minimum tax applies to the gains made after that date.

Enter the market value on 1 July 2027 on assets you will hold across the date and the calculator splits the gain, applies the CPI index numbers shown in the table above and tests the minimum tax.

Foreign residents pay capital gains tax only on taxable Australian property, and they lose the 50% discount on gains that accrued after 8 May 2012. An asset bought before that date keeps the discount on the gain up to its value on the day, if you enter that value. Tick the foreign resident box in section 3 and the calculator applies those rules and the foreign resident tax rates.

A capital loss offsets capital gains only, and never other income. You subtract this year's losses from your gains before the 50% discount is applied, and any loss you cannot use carries forward to later years with no time limit. Enter the losses from earlier years in section 3 and the calculator applies them before the discount.

The income year runs from 1 July to 30 June. A capital gain goes in your tax return as the net capital gain, and the tax return for the 2026-27 year is due on 31 October 2027 if you lodge it yourself. The calculator covers one income year at a time: a sale dated outside the year you have open is left out of the numbers.