Capital Gains Calculator
See how the same investment creates different tax bills in the US and Australia — and understand why cost basis matters.
Why the same investment can have two completely different tax bills
When you become an Australian permanent resident, the ATO treats your PR grant date as the starting point for measuring your investment gains. This means the same asset you bought in the US years ago can have a large gain in the US (measured from your original purchase) and a much smaller gain in Australia (measured only from your PR date onward).
This dual cost basis is one of the most important — and most commonly misunderstood — aspects of cross-border investing. This tool lets you enter your assets and see both gain calculations side by side, with estimated tax in each country.
Key rules this tool applies:
- US: Original purchase price is your cost basis. Short-term gains (held ≤ 12 months) taxed as ordinary income. Long-term gains (held > 12 months) taxed at 0%, 15%, or 20% depending on income.
- Australia: Your PR grant date is your cost basis. Assets held > 12 months from that date qualify for the 50% CGT discount, halving the taxable gain.
- Important: If you hold Australian-domiciled ETFs (e.g. VAS, VGS, VDHG, A200), US tax rules classify them as PFICs — a separate and punitive tax category. This tool flags those assets but does not model PFIC tax, which requires specialist advice.
Your profile
For assets bought before this date, you'll need to enter the price on your PR date to calculate your Australian gain.
Used to determine your US capital gains tax rate tier.
Your portfolio
| Ticker / Market | Qty | Buy Price | Buy Date | Live Price | Total Value | US Gain | AUS Gain | Actions |
|---|---|---|---|---|---|---|---|---|
AAPL NASDAQ | 50 | $148.00 | 15 Mar 2021 | — | — | |||
VAS ASX | 200 | A$88.50 | 20 July 2022 | — | — | |||
BTC CRYPTO | 0.5000 | $28,000.00 | 10 Jan 2023 | — | — |
Portfolio Summary
Estimated Tax (If Sold Today)
US long-term gains rate: 15% (single filer, ~$120,000 income)
PFIC-flagged assets excluded from US total
Effective Tax Rates
What this means
These are estimates to help you prepare for a conversation with a cross-border tax specialist — not a tax bill.
What this means when you sell
The gains above are unrealised — you don't owe tax until you actually sell. But understanding the estimated liability now helps you:
- Choose the best time to sell (e.g. in a lower-income year to access a lower LTCG rate)
- Understand which assets have the biggest cross-border tax gap
- Bring accurate numbers to your first meeting with a specialist
- Avoid surprises at tax time, especially for assets purchased before your PR date
One or more of your assets may be subject to PFIC rules
Australian-domiciled ETFs like VAS are likely classified as PFICs by the IRS. This means standard capital gains treatment may not apply — the IRS imposes a punitive tax regime on PFICs that can significantly increase your US liability. US tax estimates for these assets have been excluded from the summary above. This is one of the most important issues for US citizens investing in Australia — raise it explicitly with your cross-border tax specialist.
This tool provides simplified estimates for educational purposes. It does not account for state/territory taxes, the Net Investment Income Tax (NIIT), PFIC rules, tax treaty provisions, wash sale rules, or your specific deductions. Use it to prepare for a conversation with a qualified cross-border tax specialist — not as a substitute for professional advice.
Want to see how your investments fit your full picture?
Capital gains are just one piece. The GlobalTaxMate assessment looks at your complete situation — retirement accounts, PFIC rules, superannuation, and more.
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