Calculators / Australia
The 2027 property tax changes.
Australia's capital gains and negative gearing reforms are law. They start on 1 July 2027, they treat new builds differently to established dwellings, and most of the commentary about them is wrong in one direction or the other. These two calculators work the numbers on your own figures — in your browser, with the formulas and sources shown.
From 1 July 2027
Property CGT reform calculator
Compare the former 50% CGT discount with the enacted treatment: a deferred pre-2027 gain that keeps the discount, an indexed post-2027 gain, and the 30% minimum tax test.
- Splits a property held across 1 July 2027 into its two gain components
- Indexes the reset cost base and each post-2027 capital cost
- Shows the new-dwelling alternative where the 50% discount is kept
From the 2027-28 income year
Negative gearing impact calculator
See what loss quarantining does to one property's tax and cash flow — including the grandfathering cut-off, the carried-forward balance, and the new-build carve-out.
- Classifies the property against the 12 May 2026 contract cut-off
- Separates pre-tax cash flow from the tax effect on it
- Tracks the quarantined balance in and out across the year
What is actually changing
Two rules, one start date, one big carve-out.
From 1 July 2027 the 50% CGT discount is replaced by cost-base indexation for individuals, trusts and partnerships, with a 30% minimum rate of tax on the real gain accruing after that date. A property you already hold is treated as sold and reacquired at market value on 1 July 2027, so the gain up to then is deferred and keeps the discount.
From the 2027-28 income year, a rental loss on an established residential dwelling acquired after 7:30 pm ACT legal time on 12 May 2026 is quarantined — carried forward against future residential rental income or eligible residential capital gains, rather than deducted against salary. It is not abolished, and earlier contracts are grandfathered.
Qualifying new residential dwellings sit outside both rules: they keep the 50% CGT discount, they are outside the 30% minimum tax, and they stay negatively gearable. The detailed definition is set by a ministerial legislative instrument that has not been made yet, so eligibility has to be confirmed rather than assumed.
Ground rules
How these are built.
They report basic income tax only, and they show the difference between two methods rather than a tax bill. Anything outside the supported path stops the calculation instead of approximating it.
Every calculation runs in your browser. No amount you type is sent to us, stored or shared.
Each result exposes its variables, formulas, configuration version and sources, and can be copied out as plain text.
Future CPI is not knowable, so the calculator will not fabricate it. You state an inflation assumption, or enter official index numbers, and the result shows which you used.