Australian Capital Gains Tax (CGT) Calculator

There is no separate capital gains tax rate

This is the single most misunderstood point about Australian CGT: there's no dedicated CGT rate — a net capital gain simply gets added to your other assessable income for the year and taxed at your ordinary marginal income tax rate, plus the 2% Medicare levy. A A$25,000 taxable gain on top of A$90,000 of other income (both inside the 30% bracket) costs A$8,000 — a blended 32.0% on the taxable gain, not some fixed "CGT rate" you could look up in a table.

The 50% discount — and the exact order the ATO uses

Australian resident individuals get a 50% CGT discount if they held the asset for strictly more than 12 months before selling (exactly 12 months to the day doesn't qualify — you need day 366 or later). Miss the discount and the tax bill can more than double: the same A$50,000 gain costs A$8,000 extra tax when held over 12 months, but A$16,350 when held only 10 months — A$8,350 more, purely from missing the threshold.

Capital losses are subtracted before the discount is applied, per the ATO's official 8-step method — not after. With a A$10,000 carried-forward loss, the same A$50,000 gain becomes A$40,000 after the loss, then A$20,000 after the discount — costing A$6,400, A$1,600 less than without the loss. Applying the loss after the discount instead would understate how much the loss actually saves you.

Cost base: what you can add to reduce the gain

Your cost base isn't just the purchase price — it also includes incidental buying costs (stamp duty, legal/conveyancing fees, agent's commission on purchase) and capital improvements (not routine repairs). The ATO's own worked example: Rhi buys an investment property for A$500,000, pays A$15,000 stamp duty and A$1,200 conveyancing on purchase, then A$1,300 conveyancing and A$12,500 agent's commission on sale. Selling for A$600,000 gives a A$70,000 gain, and after the 50% discount (held 5 years) a A$35,000 taxable gain — half the raw gain simply from tracking every eligible cost.

Selling your home: the main residence exemption and the six-year rule

A home that's genuinely your main residence for the entire time you own it is fully exempt from CGT — no calculation needed. If you move out and rent it out, you can keep treating it as your main residence for up to 6 years after you leave (the "six-year absence rule"), as long as you don't treat any other property as your main residence during that time. Don't rent it out while you're away, and the exemption can extend indefinitely. This calculator doesn't run the exemption maths for you — if your sale might qualify, treat any figure below as an upper bound on what you could owe.

Why the same dollar gain can cost very different amounts

A A$200,000 gain (held over 12 months, A$80,000 other income) becomes a A$100,000 taxable gain after the discount — but that's large enough to push part of your income out of the 30% bracket and into the 37% bracket. The result: A$35,150 in extra tax, a blended 35.15% on the taxable gain — even though no single dollar was taxed above 37%. Compare that with example 1's A$8,000 on a much smaller gain that stayed within one bracket: a naive "multiply by your top rate" estimate gets both of these wrong. Only a full delta calculation across the brackets — what this calculator does — gets the real number.

The proposed 2027 change doesn't apply yet

A 2026-27 Federal Budget proposal would, from 1 July 2027, replace the 50% discount with an inflation-indexation method plus a 30% minimum effective rate, for assets acquired from that date. It's proposed only — the ATO's own guidance confirms it doesn't apply to Tax Time 2026, so this calculator computes current law as it stands today.