Allowance to Millionaire Calculator
See what a weekly kids allowance could grow to if it were invested every week from childhood — and how young compounding reaches a million.
How it works
Monthly = weekly × 52 ÷ 12 · FV = monthly × ((1 + r)^n − 1) ÷ r, where r = annual return ÷ 12 and n = months
A small weekly allowance looks trivial, but invested from childhood it has decades to compound. Because growth is exponential, the years added at the front — when the balance is smallest — matter most, since every early dollar keeps doubling for the longest. This is why starting a child investing at 8 rather than 28 can more than quadruple the final result, even though the extra contributions are tiny.
Worked example
A $10/week allowance is about $43.33/month. Invested from age 8 to 65 (684 months) at 8%, that grows to roughly $605,000 — from only about $29,600 actually contributed. The other ~$576,000 is compounding doing the work.
Frequently asked questions
Is investing a child’s allowance realistic?
Many families do it through a custodial brokerage (UGMA/UTMA) or a Roth IRA once the child has earned income. The point of this tool is to show the power of the time horizon, not to prescribe a specific account.
Why does starting age matter so much?
Compounding is exponential, so the earliest dollars grow for the most years. Delaying even ten years removes the periods when doubling has the biggest effect, which is why an early start often beats a much larger late start.
What return should I assume?
A diversified stock index has historically averaged roughly 7–10% before inflation. This is an assumption, not a promise — real returns vary year to year and can be negative.
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Educational estimate, not financial advice. Returns are assumed constant and are not guaranteed.