S&P 500 Calculator
Estimate how an investment tracking the S&P 500 index could grow over time. Enter your numbers below to project a future value based on your own assumptions.
Your investment
This is an assumption you choose, not a guaranteed S&P 500 return. The index has no fixed rate — try a few different values.
Estimated future value
$300,851
Based on a 7.00% assumed annual return over 20 years. This is a projection, not a guarantee.
Total contributions
$130,000
Estimated investment growth
$170,851
Estimated total return
131.42%
Year-by-year breakdown
| Year | Starting balance | Contributions | Investment growth | Ending balance |
|---|---|---|---|---|
| 1 | $0 | $16,000 | $919 | $16,919 |
| 2 | $16,919 | $6,000 | $1,419 | $24,339 |
| 3 | $24,339 | $6,000 | $1,956 | $32,294 |
| 4 | $32,294 | $6,000 | $2,531 | $40,825 |
| 5 | $40,825 | $6,000 | $3,148 | $49,973 |
| 10 | $93,671 | $6,000 | $6,968 | $106,639 |
| 15 | $168,587 | $6,000 | $12,383 | $186,971 |
| 20 | $274,790 | $6,000 | $20,061 | $300,851 |
How to invest in the S&P 500
The S&P 500 is an index — a benchmark tracking roughly 500 large U.S. companies — not something you can buy directly. Investors get exposure to it through S&P 500 index funds and ETFs built to track its performance as closely as possible, such as VOO, SPY, or IVV. This calculator uses the same standard compound-growth math regardless of which specific S&P 500 fund you're considering, since they're all trying to do the same job.
If you already know you're specifically interested in Vanguard's S&P 500 fund, see our VOO calculator for the same math with VOO-specific content, or VOO vs SPY to compare two of the most widely held S&P 500 funds.
Why use an S&P 500 calculator
An S&P 500 investment calculator turns a vague question — "what could investing in the S&P 500 become?" — into a concrete, adjustable number. By changing the initial investment, monthly contribution, time horizon, and assumed return, you can see how each factor moves the projected outcome, and compare that against your own plan.
Related Calculators
Frequently asked questions
This is an educational calculator, not financial advice.
Results shown are estimated future values based on the return assumption you enter — they are not predictions and VOO is not guaranteed to achieve any particular return. Past performance of the S&P 500 or any fund does not guarantee future results. Consider speaking with a licensed financial professional before making investment decisions.