CGT Calculator — Old vs New
Side-by-side comparison of Australia's current 50% CGT discount vs the new indexation + 30% minimum tax rules taking effect from 1 July 2027.
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Frequently Asked Questions
If you sell before 1 July 2027, you use the old 50% discount rules. If you sell after that date AND part of the gain accrued after that date, the new rules apply to that portion. Assets acquired before 12 May 2026 7:30pm AEST are grandfathered for the gains accrued before 1 July 2027.
Your purchase price is multiplied by (CPI at sale / CPI at purchase). This calculator uses your assumed annual inflation rate to estimate that ratio. Only the gain above this indexed cost base is taxed.
Under the new rules, the tax payable on net realised capital gains cannot be less than 30% of the gain. So even if your marginal rate would imply less tax, you pay at least 30%. This is the headline minimum tax floor.
Yes — to all CGT assets held longer than 12 months. The Government has signalled new-build property investors can choose between old and new systems.
No. The main residence exemption is unchanged.
Related Resources
This calculator estimates CGT under the current and proposed Australian rules. Not financial or tax advice. Final rules subject to legislation.
Last updated: 25 May 2026