Disclaimer: This calculator provides estimates only and should not be considered financial or tax advice. Always consult with a qualified tax professional or accountant before making investment decisions. This tool does not constitute advice from the Australian Taxation Office.
CGT on shares calculator inputs and results
Share Transaction Details
Purchase
Used to determine if held 12 or more months. The 50% CGT discount applies to assets held at least 12 months before sale.
Sale
Your Tax Details
Used to calculate CGT at your marginal rate. Leave blank to see tax based on the gain alone.
Enter your share transaction details above
Results update live as you type. At minimum, enter purchase price per share, number of shares and sale price per share.
How capital gains tax on shares works
When you sell shares, ETFs or units for more than they cost you, the profit is a capital gain. It is added to your taxable income for the year and taxed at your marginal rate. When you sell for less than they cost, you make a capital loss, which can reduce other capital gains but not your salary or wages. This calculator estimates the CGT on a share sale.
For shares held at least 12 months, an Australian resident individual currently reduces the taxable gain by the 50% CGT discount, so only half the net gain is taxed. Brokerage on the buy and the sell is counted, and any capital losses are applied first. This is a model and general information, not tax advice.
How to use this calculator
Enter the buy details
Add the purchase price per share, the number of shares, and the brokerage you paid to buy.
Enter the sale details
Add the sale price per share and the brokerage you paid to sell.
Add the dates and your income
Enter the purchase and sale dates and your other taxable income for the year.
Include any losses and HELP
Add capital losses to offset the gain, and turn on the HELP option if you have a study loan.
How this calculator works
The calculator works out your capital proceeds, which is the sale value less the selling brokerage, and your cost base, which is the purchase value plus the buying brokerage. The difference is your capital gain or loss. It then applies any capital losses. If you are an individual who held the shares for at least 12 months, it reduces the remaining gain by the 50% discount, adds the discounted gain to your other income, and taxes the difference at your marginal rate plus the Medicare levy.
Assumptions used
Assumptions used: brokerage on the purchase is included in the cost base, and brokerage on the sale reduces the capital proceeds, in line with ATO rules on incidental costs. Capital losses are applied before the 50% discount. The 12-month holding period excludes the day of purchase and the day of the sale, and the CGT event is taken as the contract or trade date, not settlement. The tax effect uses the marginal method against the 2025-26 rates and the Medicare levy. Shares bought at different times are separate parcels, and the calculator works out one parcel at a time using the figures you enter. The estimate assumes you are an Australian resident individual and is general information, not tax advice.
Worked example
An investor buys 5,000 shares at $4.00, which is $20,000, plus $20 brokerage, so the cost base is $20,020. More than 12 months later they sell at $6.00, which is $30,000, less $20 brokerage, so the capital proceeds are $29,980. The capital gain is $9,960.
With no capital losses, the 50% discount halves the gain to $4,980. That $4,980 is added to the investor's other income and taxed at their marginal rate plus the Medicare levy. For an investor whose marginal rate plus the Medicare levy totals 32%, the CGT on the sale is about $1,594.
The result depends on your income, your brokerage and the holding period, which the calculator uses to produce your own numbers.
What changes your capital gains tax on shares
Several things change how much capital gains tax you pay when you sell shares. The main ones are:
Holding period
Shares held at least 12 months qualify an individual for the 50% discount. Held under 12 months, the full gain is taxed.
Brokerage
Brokerage on the buy adds to the cost base, and brokerage on the sell reduces the proceeds, so both lower the gain.
Your other income
The gain is added to your income, so your marginal tax rate for the year sets the tax on it.
Capital losses
Current year and carried forward capital losses reduce the gain, and are applied before the 50% discount.
Which parcel you sell
Shares bought at different times are separate parcels with their own cost and date, which changes the gain and the discount.
Study loans
A net capital gain increases your taxable income, which can trigger or increase a compulsory HELP or HECS repayment.
Rates and assumptions used
| Item | Value used | Source |
|---|---|---|
| CGT discount for individuals (current rules) | 50% for shares held at least 12 months | ATO, How to calculate your CGT |
| Cost base and brokerage | Purchase price plus buying brokerage; selling brokerage reduces the capital proceeds | ATO, Cost base of assets |
| Order of capital losses | Applied before the 50% discount | ATO, How to calculate your CGT |
| Parcels of shares | Shares bought at different times are separate CGT assets; you identify which parcel you sell | ATO, Keeping records of shares and units |
| HELP and HECS repayment income | Repayment income is based on taxable income, which includes a net capital gain | ATO, Income tests |
| New rules from 1 July 2027 | For individuals, the 50% discount is replaced by cost base indexation and a 30% minimum tax rate | ATO, Reforming negative gearing and capital gains tax |
Figures checked against the sources above on 10 August 2026.
Frequently asked questions
Your capital gain is the sale proceeds, less selling brokerage, minus the cost base, which is the purchase price plus buying brokerage. If you held the shares at least 12 months, an individual can reduce the gain by the 50% discount. The discounted gain is added to your income and taxed at your marginal rate.
Related calculators and guides
Sources
- •ATO, How to calculate your CGT
- •ATO, Cost base of assets
- •ATO, Keeping records of shares and units
- •ATO, Income tests
- •ATO, Reforming negative gearing and capital gains tax
Content reviewed and figures checked against the sources above on 10 August 2026.