VOO Compound Interest Calculator
See how compounding affects a VOO investment over time, using monthly compounding on both your initial investment and your ongoing contributions.
Your investment
This is an assumption you choose, not a guaranteed VOO return. Try different values to see how they affect the projection.
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%
- Initial investment
- $10,000
- Total monthly contributions
- $120,000
- Investment period
- 20 years
- Assumed annual return
- 7.00%
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 compounding is calculated here
"Compound interest" is a bit of a misnomer for a stock investment like VOO — a fund doesn't pay a fixed interest rate the way a savings account does. Instead, this calculator treats your assumed annual return as if it compounds monthly, which is a common simplification used to model long-term stock market growth.
Specifically: FV = P × (1 + r/12)^(12t) for your initial investment, and a similar annuity formula for monthly contributions, where r is your assumed annual return and t is the number of years. See the full breakdown on the methodology page.
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.