Investment Calculator
Calculate your investment's future value and return on investment (ROI) over any period.
The Formula
PV = present value · PMT = monthly contribution
r = monthly rate · n = months
r = 0.08/12 = 0.006667 · n = 240
FV = 10,000 × (1.006667)²⁴⁰ + 500 × [(1.006667)²⁴⁰ − 1] / 0.006667
= $314,870
How to Estimate Investment Returns
Enter your initial investment, expected annual return rate, investment period, and any regular contributions to see your projected portfolio value over time. The calculator shows your final balance, total amount contributed, and total gain from investment returns. Keep in mind that investment returns are never guaranteed — past performance does not predict future results. But running these projections helps you understand what's realistically possible and motivates consistent saving.
What Rate of Return Should You Use?
For long-term stock market investments like index funds, 7–10% annual return is commonly used as a historical baseline. The S&P 500 has averaged around 10% annually since the 1950s, or about 7% after adjusting for inflation. For a balanced portfolio of 60% stocks and 40% bonds, 5–7% is a more conservative estimate. For a high-yield savings account or money market fund, 4–5% reflects current rates. The more conservative your investment mix, the lower the expected return — and that is perfectly fine depending on your timeline and risk tolerance.
The Importance of Regular Contributions
One of the most powerful inputs in this calculator is regular contributions. Dollar-cost averaging — investing a fixed amount on a regular schedule regardless of market conditions — removes the emotion from investing and takes advantage of market dips automatically. Someone who invests $500/month consistently will almost always outperform someone who invests a larger lump sum at the wrong time. Set up automatic transfers to your investment account and let the math work for you.
Frequently Asked Questions
What is a realistic return on investment?
For broad stock market index funds, 7–10% annually is a reasonable long-term historical expectation. Bonds typically return 2–5%. Cash and high-yield savings accounts offer 4–5% currently with FDIC protection. Your actual return depends on what you invest in, when you invest, and how long you stay invested. Over shorter time periods, actual returns can be wildly different from historical averages.
What is ROI?
Return on Investment (ROI) is the percentage gain or loss relative to the original investment. If you invested $10,000 and now have $15,000, your ROI is 50% ($5,000 gain divided by $10,000 original). ROI does not account for how long the investment took — that is where annualized return comes in. A 50% ROI over 10 years is very different from 50% over 2 years.
What is the difference between a Roth IRA and a traditional IRA?
With a traditional IRA, contributions may be tax-deductible now and you pay taxes on withdrawals in retirement. With a Roth IRA, contributions are made with after-tax money and qualified withdrawals in retirement are completely tax-free, including all the growth. If you expect to be in a higher tax bracket in retirement than you are now, a Roth is usually the better choice. Both have the same contribution limit ($7,000 per year in 2024, $8,000 if you are 50 or older).
Is it better to invest a lump sum or spread it out over time?
Statistically, lump sum investing beats dollar-cost averaging about two-thirds of the time, because markets tend to rise over time. But psychologically, most people do better with consistent monthly contributions — it removes the pressure of timing the market and keeps you from panic-selling during downturns. The best strategy is the one you can actually stick to.
How much should I have saved by age?
A common benchmark from Fidelity: have 1x your salary saved by 30, 3x by 40, 6x by 50, 8x by 60, and 10x by 67. These are rough guidelines, not hard rules. They assume you want to maintain your current lifestyle in retirement. Your actual number depends on your expected retirement expenses, Social Security income, any pension, and the lifestyle you want.
What is an index fund and why do most people recommend them?
An index fund is a low-cost investment that tracks a market index like the S&P 500. Rather than trying to pick winning stocks, index funds buy everything in the index. Because they are passively managed, their fees are very low — often 0.03–0.2% annually versus 0.5–1.5% for actively managed funds. Over 20–30 years, that fee difference compounds into tens of thousands of dollars.