Assumptions, data and tax treatment
Every figure the Australian Portfolio Lab shows is computed in your browser
from the data and rules on this page. Every default below can be changed in
the tool. Nothing you enter leaves your computer.
What the tool does
It replays a chosen portfolio mix through every historical window of
Australian financial years – FY1971 onward for mixed portfolios,
earlier for Australian-shares-only mixes – applying contributions, fees,
account-level tax and inflation, and shows the full range of outcomes:
worst, median and best. It is general information only: it does not consider
your objectives, financial situation or needs, and past performance is not a
reliable indicator of future performance.
Data sources
Historical asset-class returns: Andex Charts Pty Ltd, via the
Vanguard Asset Class Tool (retrieved July 2026), cross-checked
against Reserve Bank of Australia and Australian Bureau of Statistics
published data. Bond yields and CPI: RBA/ABS published series. The
financial-year figures used here reconcile with the numbers printed in the
published Vanguard Index Chart. Wage growth (for the "grows with wages"
contribution option): Australian Bureau of Statistics, Average Weekly
Earnings, Australia (6302.0), with the ABS predecessor series before 1983 as
compiled by the RBA in Occasional Paper 8; ABS material is published under a
Creative Commons Attribution 4.0 licence, and the series, its method and
its sources are set out in data/AWOTE_SERIES.md.
The stress test offers three preset mixes. Its monthly figures are
blended whole-portfolio returns (standard mix) and precomputed
crisis-event facts (Australian-only and international-only mixes)
derived from the sources above; the month-by-month returns for
individual asset classes are Andex Charts' compilation and are not
republished here.
The complete method and data ship with the page. The website's
calculation engine is verified, before every update, to reproduce IYI's
internal adviser tooling to the cent across tens of thousands of checks.
Asset classes and portfolio construction
- Growth assets: Australian shares and international shares (index
exposure), split 45/55 by default; US shares and Australian listed
property can be added under "More options".
- Defensive assets: Australian bonds by default, with a small cash
floor (3% of the portfolio; 8% in pension accounts). The bonds/cash
balance is adjustable.
- Portfolios rebalance implicitly each financial year (weights held
constant). Capital gains tax is not modelled along the way; at disposal
it is available for Outside-super accounts (see Tax treatment below).
The Tax view on the main page explains why.
Costs
| Fee | Default | Notes |
|---|
| Adviser and/or SMSF fee | 1.1% p.a. incl. GST (any figure
0–3%; or none), plus a fixed annual amount in dollars – $0 by default,
and where an SMSF's accounting, audit and levies are entered ($4,000
p.a. is a common figure) |
15% tax credit inside super accumulation; no credit in pension;
outside super only the advice cost that relates to tax advice is
deductible (this tool deducts none). The fixed amount is held in
today's dollars (indexed with inflation) and applies to super accounts
only – outside super the field is greyed and nothing is charged. |
| Platform (wrap) fee | 0.275% p.a. incl. GST when an adviser
is used | Same tax treatment as the adviser fee in super;
deductible at your marginal rate outside super. |
| Industry fund | Off by default; when selected, fund fees
(MER) of 0.7% p.a. flat – editable, and a figure you entered yourself
is kept rather than overwritten – plus a fixed $100 p.a. |
The MER receives no tax credit anywhere. The fixed dollars are held
in today's dollars (indexed with inflation) and get the 15% credit in
accumulation, no credit in pension. Super accounts only. It stands
independently of the adviser and SMSF costs above, and any fixed
amounts entered in both are added together. |
| Fund fees (MER) | Mean of the three biggest ASX ETF
providers' flagship index funds, per asset class | No tax credit;
subtracted from gross index returns. Editable. |
MER basis (as at July 2026)
| Asset class | Funds averaged | Mean used |
|---|
| Australian shares | VAS 0.07% · A200 0.04% · IOZ 0.05% | 0.05% |
| International shares | VGS 0.18% · BGBL 0.08% · IWLD 0.09% | 0.12% |
| US shares | VTS 0.03% · IVV 0.04% | 0.04% |
| Australian listed property | VAP 0.23% | 0.23% |
| Australian bonds | VAF 0.10% · IAF 0.10% · OZBD 0.19% | 0.13% |
| Cash | AAA 0.18% · BILL 0.07% | 0.13% |
Where a provider has no comparable flagship fund in a class, the mean uses
those available. Fund names appear here as the basis of a fee assumption,
not as recommendations.
Tax treatment
- Super – accumulation: investment income taxed at 15%
on the franking-grossed-up amount less franking credits; contributions
treated as gross concessional and taxed 15% on entry; advice and wrap
fees receive the 15% credit.
- Concessional contributions cap: in super accumulation
the before-tax (concessional) contribution is capped at $32,500 a year –
the current concessional cap – indexed with inflation along each
projection's path; any amount entered above the indexed cap is reduced
to it before contributions tax. This clamp always applies in super
accumulation.
- Division 293 (optional; high earners): an extra 15%
contributions tax you can switch on in super accumulation. With it on and
no income entered, the full 30% (the standard 15% plus the extra 15%)
applies to all concessional contributions; with a taxable income
(excluding super) entered, the extra 15% applies only to the concessional
contributions that, added to that income, exceed the $250,000 threshold.
The entered income grows each year at the contribution-growth rate. By
default the threshold is fixed at $250,000 (current law); it can
optionally rise with inflation (CPI) or at a custom rate you set.
- Pension: zero tax on investment income; franking
credits refunded in full; statutory minimum drawdowns by age are paid
out and counted in the outcomes shown; no contributions.
- Outside super: your selected marginal rate applies to
the grossed-up income less franking credits; only the advice cost that
relates to tax advice is deductible (this tool deducts none); wrap and
MER are deductible; fixed annual costs are not charged at all.
- Franking: 77% of Australian-share income franked at a 30% company
rate, from FY1988 (imputation began 1 July 1987). Where net income tax
is positive it is reduced by a credit equal to 15% of the tax.
- Capital gains tax: not modelled along the way (index funds distribute
virtually no gains – see the Tax view). At disposal it is modelled for
Outside-super accounts as an option: annual cost-base layers
(contributions plus reinvested net income), the current rules' 50%
discount (final-year additions undiscounted, held under 12 months), and
the proposed 2027 rules' CPI-indexed cost base with a 30% minimum rate
that applies at every marginal rate; indexation cannot create or increase
a loss; a sale below cost base pays no tax and no refund is implied. The
marginal rate at sale is set separately from the ongoing rate.
- Tax paid, as shown in the tool: the sum of contributions
tax (including any Division 293) and the net investment-income tax after
franking credits, charged year by year in each historical window and
expressed in today's dollars; capital gains tax at disposal is shown
separately, and is included in the tax-paid figure when the after-CGT
view is switched on. Where franking credits exceed the tax, the figure
is a net refund.
Timing conventions
- Contributions arrive mid-year and earn half the year's return.
- Contributions grow over time, in one of three ways you choose in the
tool ("Contribution growth"). Fixed: a set percentage every year, 5% by
default in super accumulation (wages and contribution caps rise), flat by
default outside super; set 0 for the same dollar amount every year. Wage
growth: each financial year's actual growth in average weekly ordinary
time earnings (AWOTE, the ABS measure of full-time adult earnings, the
same measure the concessional cap is indexed to), from a series built from
ABS 6302.0, with the ABS predecessor series, average weekly earnings, for
the years before 1983, described in data/AWOTE_SERIES.md. CPI plus a
margin: each year's inflation as set in the inflation option (actual CPI
by default; the fixed rate when that is chosen; nothing when inflation is
set to none) plus the percentage you set, so under actual CPI a margin of
0 keeps the contribution level in today's dollars.
- The concessional cap, and the Division 293 threshold when it is set to
rise, follow the same inflation path as the fixed annual costs; the Division 293
income assumption rises at the contribution-growth rate.
- Medians: with an even number of historical windows, the
upper-middle window is reported – the same convention as IYI's
desktop engine, so every view shows the same median.
- Fees and income tax are charged on the average of opening and pre-fee
closing balances.
- Pension minimums are drawn on the opening balance at the age-based
statutory rate, mid-year on average.
- "Today's dollars" deflates by actual CPI for each year of the window
(a fixed rate or no inflation can be selected instead).
- Before-inflation display: the charts arrive showing the dollars
actually in the account in each year and the corresponding money-weighted
rates, with no inflation adjustment. The
"Show in after-inflation, real dollars" switch under every chart restates
everything in today's dollars instead. Tax and contribution rules are unchanged either way – only the
display switches.
The stress test
"The cost of selling out" simulates an investor who sells everything in
the month their portfolio is first down the chosen percentage from its peak
(checked monthly from 1970 onward), then stays in cash for the rest of the
window – fees and cash-income tax continue, and any contributions keep
arriving into cash. The optional third bar sells at the lowest point of the
same fall instead. It offers three preset mixes – the standard 45/55
growth mix, Australian shares only, and international shares only, each
with bonds defensive; the custom splits under "More options" apply to the
other views. The GFC drawdown figures quoted beside the chart (Australian
shares −48%; international shares in AUD −38%; the standard 45/55 blend at
100% growth −39%; the default 70% growth portfolio −27%; peak to trough,
Jul 2007 – Jun 2009) come from the same monthly data, shipped with the
site in data/facts.json; an automated repository check
fails if the figures on this page drift from that file.
About
Built by In Your Interest Financial Planning. In Your Interest Financial
Planning Pty Ltd, ABN 28 094 300 464 is Authorised Rep. No 308161 of
Fiduciary Duty Advisers Pty Ltd AFSL No 527434. Questions and corrections
are welcome –
contact us.
