00/month for 30 years at a historical ~10% stock-market return grows to roughly $200,000 — and most of it is growth, not your deposits. See the math."> 00 a Month for 30 Years: What It Becomes | Money Scale"> 00/month for 30 years at a historical ~10% stock-market return grows to roughly $200,000 — and most of it is growth, not your deposits. See the math."> 00 a Month for 30 Years: What It Becomes | Money Scale"> 00/month for 30 years at a historical ~10% stock-market return grows to roughly $200,000 — and most of it is growth, not your deposits. See the math.">
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Investing growth

What does $100 a month invested become in 30 years?

Small, consistent investing is deceptively powerful over decades. Here's $100 a month for 30 years at the long-run S&P 500 average return.

Investing $100/mo for 30 years could grow to about $226,049.

Balance after 30 years
$226,049
Total you contribute
$36,000
Growth (compounding)
$190,049
Assumed annual return
10%

Of the ending balance, roughly $190,049 is growth you never deposited — that's compounding doing the work.

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Frequently asked questions

Is a 10% return realistic?

10% is the widely-cited long-run average annual total return of the S&P 500 (about 9.7% geometric, 1928–2025). Real returns vary year to year and inflation reduces purchasing power, so treat it as a long-horizon assumption, not a guarantee.

Where would I invest $100 a month?

A low-cost, broad-market index fund inside a tax-advantaged account (like a Roth IRA or a 401(k)) is the textbook way to capture a return like this without picking stocks.

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