What SuperCalc Pro does here: the Advanced Calculator replays your plan against every retirement start year that fits your horizon in the historical series (from 1928 onward), using year-by-year returns and Australian inflation, not one assumed return and one assumed inflation rate forever. You see worst, median, and best sustainable income, plus how Age Pension and drawdowns behaved on those paths.
Why it matters: a constant-return tool can tell you a plan “works” while the same spend would have failed if you had retired into 1973 or 2008. Sequence risk only shows up when the bad years arrive early and you are already withdrawing.
Most free super calculators still do the tidy thing: pick an average return (often around 7%), pick an inflation rate (often around 2.5%), and run a straight line for thirty years. Fine as a rough sketch; poor as a stress test. Markets deliver crashes, recoveries, and inflation shocks in clumps, which is exactly when a retiree selling units feels the damage. That is sequence of returns risk, and it is why the site also has the worst years to retire analysis separately.
Constant returns hide the years that break plans
During accumulation, a bad decade can be diluted by later contributions and time. In retirement you are selling. If prices fall early, you lock in losses to fund living costs, and the recovery starts from a smaller base. Two portfolios with the same long-run average can produce very different end balances once withdrawals start, only because the order of returns differed.
A constant 7% model never asks that question: it assumes every year is average. History is not average every year.
What historical replay actually uses
SuperCalc Pro’s historical engine walks calendar years in the stored series: separate returns for US equities, Australian shares, international shares, bonds, and cash, plus Australian CPI for that year. Your allocation weights those sleeves. Spending, fees, minimum drawdowns, and Age Pension (where you switch them on) update year by year on each path. That is the same multi-asset construction described in the phased retirement couples article method notes, not a single equity index dressed up as a diversified portfolio.
For a given horizon (say 30 or 34 years), the tool steps every start year that still has enough history left. Adjacent starts overlap, so the set of windows is not a set of independent random samples; treat the spread of outcomes as a picture of historical variability, not a formal confidence interval. Past paths are not a forecast of the next crash.
Why 1970s-style years still matter
Stagflation and early-retirement drawdowns hit purchasing power from both sides: markets soft, prices rising, withdrawals continuing. Dot-com and GFC paths test different shapes of damage (equity crashes with different inflation backdrops). The point of replaying many starts is not to pick a favourite scare year; it is to see whether your spend and allocation still leave a floor you can live with when the first decade is ugly.
Historical mode: same plan, many start years, look at worst-case sustainable income, not only the median.
How to read the results
- Note the worst start year sustainable income. That is your historical floor under the stated rules.
- Compare it to the median. A wide gap means sequence risk is doing a lot of work for your inputs.
- Check the year-by-year income sources: wages (if phased), super drawdowns, Age Pension. Constant-return tools usually cannot show that mix shifting correctly.
- Then run Monte Carlo on the same inputs. If the two methods disagree sharply, dig into assumptions before you raise spending.
If the historical floor looks uncomfortable
Common levers: lower the spending target, delay retirement a year or two, keep more cash for the early years, or use a withdrawal rule that can flex after bad markets. None of those are advice for your household, they are the knobs the calculator exists to turn so you can see the trade-offs yourself.
Official sources
Rules and rates change. Cross-check current guidance before you act:
ASIC MoneySmart: retirement planner
Replay history on your numbers
Same plan, every start year that fits: worst and median sustainable income with Australian Age Pension rules, not a flat 7% forever.
Run Advanced Retirement CalculatorDisclaimer: General information only, not personal financial advice. SuperCalc Pro Pty Ltd does not hold an Australian Financial Services Licence (AFSL). Past market sequences do not predict future returns. Historical backtesting shows how a stated strategy would have performed under past conditions, not how it will perform next. Confirm current rules with the ATO and Services Australia, and speak to a licensed adviser for advice about your situation.