Run the numbers
2026-27 Federal Budget

CGT new rules vs current law —
how much will you really pay?

Model your capital gains tax under both the 50% discount regime and the 1 July 2027 reforms (CPI indexation + 30% minimum), and see how the negative gearing changes hit your deduction.

50%Current discount
30%New minimum rate
CPIIndexed cost base
Example comparison
Tax — current law$26,689
Tax — new rules$28,892
+$2,203 more under new rules ▲

Asset details

Format: dd/mm/yyyy
Format: dd/mm/yyyy
Implied pre-tax capital growth — Derived from purchase / sale prices and holding period.

Acquisition & disposal costs

Stamp duty, conveyancing, loan fees.
Agent commission, marketing, legal.

Your tax position

47% marginal
Salary plus other taxable income (CGT is assessed per individual). Progressive FY 2027-28 brackets apply below (incl. 2% Medicare levy on income above $18,200). Drag the slider or type a value.
Affects: new rules Indexes the cost base so only the real gain above inflation is taxed. Higher CPI → lower new-rule tax. Current Law card is unaffected.
Proceeds after tax — Cash in hand: sale price less selling costs minus tax.
Profit after tax — After-tax gain: proceeds minus cost base minus tax.
Tax — Under the rules applicable at your sale date.
After-tax return — Annualised CAGR on invested capital after CGT.
Tax difference (new − current)
—
Enter your numbers to see the comparison.
Current law

50% CGT discount

Tax payable—
Gross capital gain—
Taxable after 50% discount—
Proceeds after tax—
From 1 Jul 2027

CPI indexation + 30% minimum

Tax payable—
Pre-2027 portion (50% discount)—
Post-2027 portion (indexed)—
Proceeds after tax—

Detailed calculation breakdown

Gross capital gain Net sale proceeds − cost base.—
Net cost base (incl. costs) Purchase price + acquisition costs.—
Net sale proceeds (less costs) Sale price − selling costs.—
Transitional split (assets owned before 1 Jul 2027)
Asset value at 1 Jul 2027 ATO geometric apportionment: cost base × (proceeds/cost base)^(pre-reform years / total years).—
Pre-2027 gain (50% discount applies)—
Pre-2027 taxable after 50% discount—
Indexed cost base of post-2027 portion—
Post-2027 taxable (real) gain—
Minimum-tax top-up (if marginal < 30%)—
Total taxable under new rules—
Tax comparison
Tax, current law (50% discount)—
Tax, new rules—

Tax-bracket stacking · FY 2027-28

Capital gains are added to your assessable income and taxed progressively. Larger gains can push slices into higher brackets.

Your income: — Taxable gain: — Total income for stacking: —
BracketRateFilled by incomeGain in sliceTax on gain
Total——

Strategy comparison

Compare the NPV of total tax saved under two regimes:
• Old rules — claim the loss against wages each year (immediate refund)
• New rules — carry losses forward, offset against CGT at sale (one lump sum, later)

Treasury cameo uses $14,810 (3.1% yield, 5.7% rate on a $1m property).
FY 2027-28 brackets (incl. 2% Medicare). The typical marginal rate while collecting rent and paying interest — i.e. your salary bracket. Most working investors sit at 32% / 39% / 47%.
The capital gain itself pushes income upward, and the new CGT rules apply a 30% minimum tax on post-2027 real gains — so the sale-year rate cannot drop below either floor.
Used to compare cash flows across years. 4-6% is typical for property investors. Higher rate makes earlier cash worth relatively more — favours old rules.
Old rules — NPV of tax saved — Annual refund = loss × hold-period rate, discounted each year.
New rules — NPV of tax saved — Lump sum at sale = loss × years × sale-year rate, discounted to today.
NPV difference (new − old)
—
Adjust the sliders to see which strategy wins.

Breakeven discount rate

The discount rate at which both strategies have the same NPV. Below this rate, new rules win (rate arbitrage beats time value). Above it, old rules win (immediate cash is worth more).

Breakeven r = —

Sensitivity to discount rate

rOld NPVNew NPVDiffWinner

The hidden assumption

New rules can win when your sale-year rate is higher than your hold-period rate — that's the rate arbitrage (e.g. 47% − 37% = 10pp on every dollar of accumulated loss). If you sell in a low-income year, the arbitrage disappears and old rules win clearly. New builds remain exempt from the negative gearing changes regardless of purchase date.

What's changing — and what isn't

📈

CPI indexation

Cost base uplifted by CPI over the holding period. Only the real gain above inflation is taxed under the new rules.

🛡️

30% minimum rate

A floor rate of 30% applies to real capital gains accruing from 1 July 2027. No impact on those already taxed at 30%+. Means-tested payment recipients exempt.

🏗️

Negative gearing limited

Losses on established residential properties bought after 12 May 2026 can only be deducted against future residential property income or CGT. New builds preserved.

✓

What's NOT changing

Main residence exemption · SMSF treatment · pre-12 May 2026 holdings · CGT on assets sold before 1 Jul 2027 · 50% discount on pre-2027 portion of gains.

Common questions

Do the new CGT rules apply to assets I already own?

Only to the portion of gain accruing after 1 July 2027. Gains accrued before that date keep the 50% discount under the transitional split, calculated either by independent valuation or the ATO apportionment formula.

Does the 30% minimum hit high-income earners?

No. If your marginal rate is already 30% or higher, the minimum has no effect. It targets gains that would otherwise be taxed below 30%.

What about my main residence?

The main residence exemption is unchanged. These reforms only affect CGT assets that don't qualify for that exemption.

How does negative gearing work for new builds?

New builds are exempt from the negative gearing changes — losses remain deductible against any income. Established properties bought after 12 May 2026 are restricted from 1 July 2027.

Is this financial advice?

No. This tool is for educational purposes only. It doesn't account for accumulated capital losses, depreciation recapture, main residence apportionment, company/trust structures, or your personal circumstances. Speak to a registered tax adviser.