Millionaire Calculator
From what you have and what you add monthly, at an assumed return: the years and months to a million — or to any goal you set. It also shows how much of the finish line growth builds for you.
A finish line, a pace, a date
The million is arbitrary — the calculator accepts any goal — but the structure is universal: a starting sum, a monthly habit, an assumed return, and the compounding that binds them. The answer is a duration, and durations can be planned around in a way that 'someday' cannot.
Smallest number of months where: balance compounded monthly + accumulated deposits ≥ goal
Example: $25,000 in place, $750 a month at 7%: the balance crosses $1,000,000 in about 24 years. Double the deposit to $1,500 and it takes about 17 years — the deposit lever cuts 7 years; raising the assumed return to 9% would cut fewer than 4, and you do not control that lever.
Read the contribution split before celebrating
The result separates what you deposit from what growth deposits. In nearly every realistic run, growth writes the majority of the final million — which is the entire argument for starting before the deposit feels adequate. Time in the compounding is the ingredient money cannot buy later.
How this is calculated
A month-by-month simulation: balance grows at return ÷ 12, the deposit lands at month end, and the first month the balance reaches the goal is reported (converted to years and months). Contributions summed exactly; growth is the remainder to the goal line. Assumes a constant return — the smooth-line warning from the investment page applies here in full.
Frequently asked questions
Why does the time barely move when I raise the return?
Because contributions dominate early balances — the return acts on a small base. Late in the journey the balance is large and return dominates, which is why early deposits matter out of proportion to their size.
Is a million the right goal?
It is a round number, not a budget: the retirement calculator works from the spending side (what the money must fund), which is the more meaningful finish line. Use this page for motivation and that one for planning.
What if I can only save irregularly?
Model the average: an honest average monthly figure beats a perfect irregular schedule in planning value. Lump sums can be added to the starting amount as they arrive, re-running the page each time.
Does this account for inflation?
No — a million in 24 years is not today's million (run the inflation page at 3% and it is about $490,000 of today's purchasing power). Set the goal in future money terms if the distinction matters to you.
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