Capital Gains Tax Calculator (Investment Property)

How Capital Gains Tax Works on Investment Property

Capital gains tax (CGT) is not a separate tax in Australia. Instead, your net capital gain for the year is added to your other taxable income and taxed at your marginal tax rate. For investment properties, the starting point is to calculate your cost base and your capital proceeds.

The calculator above follows the basic steps used on the ATO capital gains schedule: work out your net capital gain, apply any discounts, then estimate the additional tax payable by comparing tax with and without the gain.

What Goes Into Your Cost Base?

Your cost base for CGT purposes is more than just the purchase price. Many property investors accidentally understate their cost base and overpay tax. Common items that may form part of your cost base include:

• Purchase price of the property
• Stamp duty and transfer fees
• Legal and conveyancing fees on purchase
• Buyer's agent fees (if capital in nature)
• Capital improvements and major renovations
• Selling costs such as agent commission, marketing and legal fees

Routine repairs and maintenance are generally deductible in the year they occur and do not increase your cost base. The calculator allows you to separately enter capital improvements and selling costs so you can see the impact on your gain.

50% CGT Discount and SMSF Discount

If you are an Australian resident individual or trust and you have held the investment property for at least 12 months, you generally qualify for the 50% CGT discount. This means only half of the net capital gain is added to your taxable income. Complying super funds usually receive a one-third discount (two thirds of the gain is taxable), and companies do not receive a CGT discount at all.

The calculator lets you toggle eligibility for the discount and choose between individual, SMSF and company ownership so you can see how the structure affects your CGT bill and after-tax outcome.

CGT and Your Marginal Tax Rate

Capital gains are effectively taxed at your marginal tax rate for the year, after taking into account any discount. If the gain pushes you into a higher tax bracket, part of the gain may be taxed at a higher rate. This tool estimates the additional tax by calculating tax on your other taxable income alone, then tax on your income plus the discounted gain, and taking the difference.

This makes it easy to answer practical questions like: “If I sell this property this year, how much extra tax will I pay?” and “What is my effective CGT rate on this sale?”

Important Limitations

This calculator is a general guide only. It assumes:

• You are an Australian resident for tax purposes;
• The property is an investment property (no main residence exemption);
• No small business CGT concessions apply;
• No foreign resident withholding or complex trust distribution rules;
• Current year tax rates and Medicare levy apply for the full year.

Your actual tax position may differ, especially if you have multiple properties, carried-forward capital losses or complex structures. Always confirm results with a registered tax agent or financial adviser.