I believe the capital gains tax rules are like this: If you...

I believe the capital gains tax rules are like this: If you purchased $10,000 shares 3 years ago and you sell them for $20,000. First thing you do is index the cost. This means if inflation was 3% in each of the 3 years, your new indexed cost base is $10,900 (approx, this ignores compounding). OK, so now your capital gain is $20,000 - $10,900 = $9,100. 50% of that is included in your personal tax return. i.e. $4,550. So if you're working or have any other taxable income, this $4550 is added to your other taxable income. Say's you're other taxable income is $100,000. Now it's $104,550 which is taxed at the marginal tax rate The marginal tax rate for this much taxable income is 32.5%. So in effect, the capital gain is taxed at 32.5% which is tax of $1,479. Not too bad, your shares went up by $10,000 and you keep $8,521.

But everyone's marginal tax rate is different. You're might be 32.5%, mine might be 19%.

If you are earning much less other income, you'll be on a lower marginal rate. Let's say your other taxable income is $12,000. Add the capital gain of $4550. Now taxable income is $16,550. That is less than the tax free threshhold of $18,200, so you don't pay any tax on the $16,550.

The other thing to take into account is capital losses either from the current year or from past years. If you made a capital loss last year of $3000, which was also calculated after indexing the cost base and taking 50% etc, you offset that capital loss against this capital gain and the difference is added to your personal taxable income. i.e. $4550 gain less $3000 loss = net capital gain of $1,550. Add $1,550 to your personal taxable income and pay tax at the applicable marginal rate.

Not financial advice. This was only my understanding of capital gains tax for individuals. I have no idea about companies or SMSFs. Good luck