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Results are hypothetical illustrations based on the numbers you enter and simple assumptions: a constant return, with no taxes, fees or inflation unless stated. They are not predictions or guarantees; real returns vary from year to year and can be negative, and investing can lose money. Educational content only. Not financial advice. See our Disclaimer.
Quick answer: To reach $1,000,000 by 60 at an 8% average return, invest about $287 a month starting at 20, $671 a month starting at 30, or about $1,700 a month starting at 40. Starting 10 years earlier cuts the monthly amount by more than half. Hypothetical, not guaranteed.
How much do I need to invest to be a millionaire?
It depends almost entirely on one thing: how many years you give it. At an 8% return, $1,000,000 by 60 costs about $287 a month if you start at 20, $671 a month starting at 30, and about $1,700 a month starting at 40. Same goal, same return — the only difference is the start date.
Why the early years matter most
The first $100,000 is the slowest; after that, growth does more of the lifting than you do. In the chart, notice the point where the gold line pulls away from the dashed contributions line — that is where your money starts earning more than you add.
Already have savings?
Enter what you have invested today and the monthly number drops, sometimes dramatically. $50,000 invested at 30 cuts the monthly needed for $1M by 60 roughly in half.
Watch: the $200/month millionaire math
60-second version
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Open calculator →Questions people ask
How much should I invest monthly to be a millionaire by 40?
Starting at 25 with nothing, about $2,900 a month at an 8% return. Starting at 20, about $1,700 a month. Use the calculator for your exact age and return.
Is 8% a realistic return?
It is in line with the long-run average of a broad US stock index fund with dividends reinvested (about 10% before inflation). Returns vary a lot year to year, so treat it as a planning number, not a promise.
Does becoming a millionaire require picking stocks?
No. The numbers here assume a plain diversified index fund and consistency. Time and regular contributions do the work.
How long does it take to become a millionaire investing $500 a month?
About 33 years at an 8% average return, starting from zero. $1,000 a month takes about 25.5 years; $200 a month about 44 years.