Question 1

What return should I use?

Accepted Answer

For a broad equity index over long periods, 6–8% nominal is the range most planners use. For a balanced portfolio, 4–6%. For a savings account, use the actual posted rate. Anything above 10% is a forecast, not a plan.

Question 2

Why does the growth line stay flat for so long?

Accepted Answer

Because compounding is multiplicative and your balance starts small. The first decade is almost entirely your own deposits. The curve only bends once the balance is large enough that the return on it exceeds what you can save.