Australian Capital Gains Tax Calculator
Use this calculator to estimate your taxable capital gain and the extra tax that may apply. It is designed for Australian residents and gives an estimate only.
Assumes resident individual tax brackets for estimate purposes. Does not include all ATO adjustments, exemptions, or special cases.
How capital gains tax works in Australia
In Australia, capital gains tax (CGT) is not a separate tax. Instead, your net capital gain is added to your taxable income and taxed at your marginal rate. That means two people can sell the same asset for the same gain and pay very different tax depending on their total income, losses, and eligibility for CGT discounts.
Basic formula
A simple way to think about it is:
- Capital proceeds (usually sale price)
- minus Cost base (purchase price + eligible costs + improvements)
- minus Capital losses
- minus CGT discount (if eligible)
- equals Net capital gain included in tax return
What this calculator includes
This calculator is built for quick planning and cash-flow forecasting. It includes major moving parts most people ask about:
- Purchase and sale values
- Buying and selling transaction costs
- Capital improvement costs
- Carried-forward capital losses
- Holding period (to check discount eligibility)
- Taxpayer type (individual/trust, super fund, or company)
- Estimated additional tax based on other taxable income
When the 50% discount applies
For many individuals and trusts, the popular CGT discount can reduce the taxable gain by 50%, but only when eligibility rules are met. A key condition is that the asset is generally held for at least 12 months before sale. Companies are not eligible for this discount, and complying super funds usually receive a one-third discount instead.
Important nuance about losses
Capital losses are generally applied before discounts. That order matters. If you have losses from previous years, they can significantly reduce or eliminate your taxable gain before any discount is calculated.
Step-by-step example
Suppose you bought an asset for $450,000, paid $18,000 in buying costs, added $25,000 of capital improvements, and later sold it for $620,000 with $14,000 selling costs.
- Cost base = 450,000 + 18,000 + 25,000 = 493,000
- Net sale proceeds = 620,000 - 14,000 = 606,000
- Gross gain = 606,000 - 493,000 = 113,000
- Less carried-forward losses (say 5,000) = 108,000
- If held 12+ months as individual/trust: 50% discount = 54,000
- Net capital gain included in tax return = 54,000
From there, tax depends on your total taxable income. The calculator estimates the extra tax by comparing your tax before and after adding that net capital gain.
Common mistakes people make
- Forgetting buying and selling costs that can be included in cost base
- Assuming all renovation spend is eligible as capital improvements
- Applying the 50% discount when the 12-month rule is not met
- Trying to offset salary income with capital losses (generally not allowed)
- Ignoring the timing of contracts, which can affect tax year treatment
Frequently asked questions
Does this tool work for shares, property, and crypto?
Yes, as a high-level estimate. But each asset class can have specific rules, records, and events that affect calculation details.
Is the tax estimate exactly what I will pay?
No. This is a planning estimate only. Your final result may differ due to offsets, deductions, residency status, concessions, and ATO-specific methods.
Can I use this for small business CGT concessions?
Not directly. Small business concessions can materially change outcomes and usually require specialist advice.
Final thoughts
A solid capital gains estimate helps you make smarter choices about selling timing, expected tax, and after-tax cash in hand. Use this calculator to model scenarios before you act, then validate with a tax adviser before lodging your return.