Project the growth of your investment over time with regular contributions and compound returns.
Rates as of Q2 2025 (example)
An investment calculator projects how an investment portfolio could grow over time, based on an initial amount, regular monthly contributions, an expected annual rate of return, and a time horizon. It shows your projected final balance along with a breakdown of how much came from your contributions versus how much came from investment growth — useful for comparing different investing scenarios.
This calculator compounds returns monthly. Each month, growth is calculated on the current balance, then your monthly contribution is added before the next month's growth is calculated.
Formula (with monthly contributions): Balance grows each month as Balance = Balance × (1 + r) + contribution, where r is the annual return rate ÷ 12.
Example: Starting with $10,000, contributing $300 per month, at a 7% annual return (example rate — actual returns are not guaranteed and vary with market conditions) over 15 years, the projected balance grows substantially, with a meaningful share coming from compound growth rather than contributions alone. (Note: all figures in this example are for illustration purposes only and do not represent actual rates or market conditions.)
US investors have access to a wide range of account types and asset classes — brokerage accounts, IRAs, 401(k)s, index funds, ETFs, individual stocks, and bonds, each with different risk and return characteristics. The 7% default return in this calculator is a commonly cited illustrative example for a diversified stock-heavy portfolio over the long term, not a guaranteed or predicted return for any specific investment — more conservative portfolios (with more bonds) typically have lower expected returns and lower volatility. Actual investment returns fluctuate significantly year to year and can be negative, so this calculator works best for long-term planning rather than predicting a specific outcome.
It depends heavily on your asset allocation. A stock-heavy portfolio has historically had higher average returns over long periods but with more volatility, while a bond-heavy portfolio tends to have lower but steadier returns. The 7% default is an example only — not a guarantee for any specific portfolio.
This calculator compounds returns monthly. Each month, growth is calculated on the current balance, then added to it along with your monthly contribution before the next month's growth is calculated.
No. This calculator assumes a constant annual return rate for simplicity. In reality, investment returns vary significantly year to year — some years positive, some negative — even if the long-term average matches your assumption.
A significant amount over long time horizons. Contributions made earlier have more time to compound, so consistent monthly investing — even modest amounts — can substantially increase your final balance compared to a single lump sum of the same total.
No. Taxes on investment gains (which vary by account type) and investment fees (such as fund expense ratios) are not included, and both would reduce your real-world returns compared to the projection shown.
No. The projected balance is shown in nominal terms without adjusting for inflation, which reduces the real purchasing power of that balance over time, especially over long time horizons.
Disclaimer: The information, rates, and figures provided on this page are for educational and illustrative purposes only. All rates and examples shown are sample values and do not reflect current or actual market rates or guaranteed investment returns. Financial rules and regulations change frequently. Always consult a qualified financial advisor before making any financial decisions.