Calculators

Australian CGT calculator for shares

Estimate the capital gains tax on a share sale. Applies the 50% discount for assets held over a year, offsets capital losses before the discount, and stacks the gain on top of your income across FY2025-26 resident brackets.

Your trade

Purchase price total (A$)

What you paid for the parcel of shares.

Sale price total (A$)

What you sold the parcel for.

Brokerage & costs total (A$)

Buy and sell brokerage — added to your cost base, reducing the gain.

Held longer than 12 months?

Resident individuals get a 50% CGT discount on assets held over a year.

Taxable income excluding this gain (A$)

Salary and other taxable income for the year — the gain stacks on top of this.

Capital losses to offset (A$)

Prior or current-year capital losses. Applied before the 50% discount.

Estimate

Gross capital gain: –
Gain after losses: –
Taxable gain (after discount): –
Estimated CGT: –
Effective rate on gross gain: –
Net sale proceeds after CGT: –

Estimate only. Resident individual rates for FY2025-26, Medicare levy applied as a flat 2% on income above $45,000. No low-income offsets, surcharges or other levies are modelled. Not tax advice.

How CGT works on Australian shares

There is no separate capital gains tax in Australia — a capital gain is simply added to your assessable income for the year and taxed at your marginal rate. A CGT event happens when you dispose of an asset, which for shares almost always means selling them. Until you sell, an unrealised paper gain is not taxed, no matter how much the price has moved.

Your gain is the sale price minus the asset's cost base. The cost base is more than just what you paid for the shares — it includes brokerage on both the buy and the sell, plus other incidental costs of acquiring and disposing of them. Rolling brokerage into the cost base is what reduces the taxable gain, which is why this calculator adds your costs there.

If you held the shares for more than 12 months, a resident individual gets a 50% CGT discount — only half the gain is taxed. The 12 months runs from the day after you acquired the shares to the day of the CGT event, so a parcel bought and sold on the same calendar dates a year apart does not quite make it.

Capital losses are applied before the discount, not after — and this ordering matters. Losses (from this year or carried forward from prior years) reduce the gross gain first; the 50% discount is then applied to whatever remains. Applying the discount first would halve the gain and understate how much of it your losses can absorb, so getting the order wrong inflates the tax you think you owe. Capital losses can only be offset against capital gains, never against your salary, and any unused losses carry forward indefinitely to future years.

Finally, the discounted gain stacks on top of your other income. Because the brackets are progressive, a large gain can push part of itself into a higher bracket, so the right way to work out the tax is tax on (income + gain) minus tax on income — not the gain multiplied by a single marginal rate. This calculator does exactly that.

Worked example

You buy $10,000 of shares, pay $40 brokerage, and sell 18 months later for $15,000. Your gross gain is $15,000 − $10,000 − $40 = $4,960. With no capital losses to offset and the 50% discount (held over a year), the taxable gain is $2,480. On a $90,000 salary that $2,480 sits entirely in the 30% bracket, and with the 2% Medicare levy the marginal rate is 32% — an estimated CGT of about $794, leaving roughly $14,206 of the sale proceeds after tax.

Common questions

Do I pay CGT if I just hold the shares forever?+

No. CGT is only triggered by a CGT event — for shares, that's disposing of them, normally by selling. An unrealised gain on shares you still hold is not taxed, however far the price has risen. The tax crystallises only when you sell (or otherwise dispose, such as gifting or a company being taken over).

Can capital losses offset my salary?+

No. Capital losses can only be offset against capital gains — never against salary or other ordinary income. If your capital losses exceed your capital gains for the year, the unused portion carries forward indefinitely and can be used against gains in future years.

When does the 12 months for the discount start?+

The holding period runs from the day after you acquired the shares up to the date of the CGT event (usually the contract date when you sell). You need more than 12 months — exactly a year is not enough — to qualify a resident individual for the 50% discount.

Why apply losses before the 50% discount?+

Because that's the order the rules require, and it works in your favour. Losses reduce the full gross gain first, then the discount halves whatever remains. Applying the discount first would waste half of each loss dollar against an already-halved gain, overstating the tax. This calculator offsets losses before discounting.