Your number
Yearly spending ÷ rate, to the nearest $1,000.
The maths
How the forecast is worked out.
The formula, the assumptions behind it and the cases where the estimate can mislead.
The monthly calculation.
Each month the balance grows and your monthly amount is added, until you reach your number.
Balance
(1 + growth ÷ 12)
Monthly amount
Repeats until your goal, for up to 60 years.
Five steps to a date
Where you are
Assets minus debts.
What you add
The monthly amount you enter. The dashboard’s speed tile is different.
Growth per year
Median of your last 12 months, compounded, capped at 15%. Under 30 days of history, or flat months: a flagged 6%. Or type your own.
Three versions
Cautious is growth minus 3 points, to a floor of 0. Optimistic is plus 3.
A worked example.
A household with $45,000 adds $1,000 a month and spends $50,000 a year. At 4% the number is $1,250,000. Adding $200 a month at 6% arrives 2.1 years (25 months) sooner.
- Cautious44years3% a year
- Base30years6% a year
- Optimistic23years9% a year
Where it can mislead.
Growth includes savings
Savers often hit the 15% cap.
Fixed dollars
Use growth after inflation for today’s money.
Straight lines
Real markets rise and fall.
A rule of thumb
4% came from US research on 30-year retirements.
Milestones every 5%.
Trend lines follow your real pace, so they look steep on small balances.
Does it use inflation?
Only if you give it a rate after inflation. Die with zero works in today’s dollars.
What does “not within 60 years” mean?
Your balance doesn’t reach your number in 720 months. Add more each month, or aim lower.
Is anything sent to work it out?
The forecast is worked out in the app from the numbers you entered.
Enter your numbers.
The forecast runs in the app from the values you enter.
