At a 7% annual return, $100,000 grows to about $200,966 in 10 years — roughly doubling. But after 3% inflation, it only buys what about $149,538 buys today. Both numbers matter.
Where does 7% come from? It’s the approximate long-run real (inflation-adjusted) return of the S&P 500 — about 10% a year in nominal terms since 1926, per long-run data compiled by NYU Stern’s Aswath Damodaran (Source: NYU Stern historical returns).
Run your own numbers on our Compound Interest calculator.
$100,000 at different returns, 10 years
| Annual return | Value after 10 years | Growth |
|---|---|---|
| 4% | $148,853 | $48,853 |
| 6% | $181,169 | $81,169 |
| 7% | $200,966 | $100,966 |
| 8% | $222,752 | $122,752 |
| 10% | $273,372 | $173,372 |
The difference between 4% and 10% is over $120,000 on the same $100,000 — which is why the return assumption matters more than most people think.
After inflation: the real number
Inflation quietly eats into nominal growth. At 3% average inflation, the $200,966 in 10 years has roughly the buying power of $149,538 today. At 5% inflation, that drops to about $123,384. Use our Inflation calculator to see the real value for any scenario.
The 3% figure is the long-run average: CPI-U (the Consumer Price Index for All Urban Consumers) has compounded at roughly 3% a year since 1913 (Source: U.S. Bureau of Labor Statistics CPI).
What about 20 years?
Time roughly quadruples the effect: the same $100,000 at 7% grows to about $403,392 in 20 years. See the full breakdown in our article What Will $100,000 Be Worth in 20 Years?.
Frequently asked questions
Is 7% a realistic return?
It’s a common long-term assumption for a diversified stock portfolio, but actual returns vary year to year. This is a projection, not a guarantee.
Should I add contributions on top?
Adding monthly contributions dramatically increases the result. Try the Compound calculator to model $100,000 plus ongoing savings.
Is this taxable?
The numbers are before tax. Realized gains and withdrawals may be taxed depending on your account type and country.