Investment Return Calculator
See the power of compound growth — project the future value of your investment.
How to use
- Enter your initial investment and monthly additions.
- Enter the expected annual return and time horizon.
- Click Calculate to see the future value, total invested, and earnings.
Estimates only — not financial advice. Actual returns vary and past performance does not guarantee future results. Verify important decisions with a qualified professional.
What Is an Investment Return Calculator?
An investment return calculator projects what a lump sum plus regular monthly contributions could grow into over time at an assumed rate of return. It is the natural partner of the compound interest calculator, with one addition that reflects how most people actually invest: not in a single deposit, but paycheck by paycheck, month after month, into a brokerage account, IRA, or workplace plan. Small monthly contributions, given enough years, routinely grow larger than the original investment itself.
The projection separates your pile into its three sources — the money you put in at the start, the money you added along the way, and the growth the market contributed. That split is instructive: in the early years, nearly all of the balance is your own contributions, but over long horizons the growth portion typically overtakes everything else. It is the clearest possible demonstration of why starting early matters more than starting big.
How to Use the Investment Return Calculator
- Enter your initial investment — the amount you are starting with today (enter 0 if you are starting from scratch).
- Enter your planned monthly addition.
- Enter the expected annual return. Broad US stock market returns have historically averaged around 10% before inflation over very long periods, but vary enormously by decade and are never guaranteed.
- Enter the investment period in years and click Calculate to see the projected future value and its breakdown.
What Return Should You Assume?
The honest answer is that nobody knows, which is why planners test several rates rather than trusting one. A diversified stock portfolio might be modeled at 6–8% for cautious planning; bonds and cash-like holdings would be lower. Using a range shows you whether your goal survives a mediocre outcome, not just a great one. Also remember the calculator assumes a smooth return each year, while real markets deliver their average through violent ups and downs — the destination estimate can still be useful even though the ride will not look like the line.
Tips for Long-Term Investors
- Increase the monthly contribution whenever income rises; the calculator shows how a small raise in contributions compounds into a large difference.
- Fees compound against you — a fund charging 1% a year hands a noticeable slice of your final balance to the provider over decades.
- Judge results in real terms: subtract expected inflation (often ~3%) from your assumed return to think in today's purchasing power.
Does this calculator guarantee my investment will reach the projected value?
No. It illustrates what would happen if your investments earned exactly the rate you entered, every year, with no taxes or fees. Real returns vary year to year and can be negative, so treat the result as a planning scenario, not a prediction or a promise.
How much difference does a monthly contribution make?
A large one over time. Because each contribution starts compounding from the month it lands, regular additions early in the period are worth far more than the same additions later. Use the calculator to compare your current monthly amount with a slightly higher one — the gap over 20 or 30 years is often surprising.
What is a realistic rate of return to enter?
It depends on what you own. Long-run US stock market averages are often quoted near 10% nominal (about 7% after inflation), balanced portfolios lower, and savings accounts lower still. For retirement planning, many people deliberately model 6–7% for stocks to stay conservative. The figure is an assumption, so test your plan at a lower rate too.
Are taxes and inflation included in the result?
No. The projection is a nominal, pre-tax figure. Account type (taxable, traditional, or Roth) changes what you ultimately keep, and inflation reduces what the final sum will buy. Both are worth modeling separately once you have a baseline projection.