Shares CGT Calculator
Calculate capital gains tax on your Australian share sales, including brokerage and the 50% long-term discount.
How CGT on Shares Works in Australia
Every time you sell shares, the Australian Taxation Office (ATO) treats it as a CGT event. The capital gain is the difference between your net sale proceeds and your cost base — it is then added to your other income and taxed at your marginal rate.
What Goes Into the Cost Base?
The cost base of your shares is not just the purchase price. It also includes brokerage fees paid at the time of purchase, as well as any other incidental costs of acquisition. When you sell, brokerage fees reduce your net capital proceeds. Getting this right reduces your taxable gain legitimately.
The 50% CGT Discount
Shares held for more than 12 months before disposal qualify for the 50% CGT discount. This means only half of the capital gain is included in your assessable income. For example, if you made a $20,000 gain on shares held for 18 months, only $10,000 is added to your taxable income. This discount is one of the biggest advantages of long-term share investing in Australia.
How the Tax Is Calculated
The taxable portion of your capital gain is stacked on top of your other income for the year. The calculator works out the marginal tax difference — that is, what you would pay in income tax with the gain versus without it. This is the most accurate way to estimate CGT because it accounts for where you sit in the tax brackets.
2025–26 Marginal Tax Rates
- $0–$18,200: 0% (tax-free threshold)
- $18,201–$45,000: 16%
- $45,001–$135,000: 30%
- $135,001–$190,000: 37%
- Over $190,000: 45%
The Medicare Levy (2%) applies separately to most income above the low-income threshold. CGT is calculated inclusive of Medicare Levy in this calculator.
Capital Losses
If you sold other shares at a loss in the same year, those capital losses reduce your capital gains before the 50% discount is applied. Unused losses carry forward indefinitely. This calculator does not include capital loss offsets — use the General CGT calculator for that.