Investment Calculator
Calculate future value of investments with regular contributions. See year-by-year growth and inflation-adjusted returns.
Results
Future Value
$298,071.87
Inflation-adjusted: $164,959.25
$168,072
Total Earnings
Initial Investment
Contributions
Earnings
Initial Investment
$10,000
Total Contributions
$120,000
Total Earnings
$168,071.87
Inflation-Adjusted
$164,959.25
Future Value Formula
FV = P(1+r)^n + PMT x [((1+r)^n - 1) / r]
P = principal, PMT = contribution, r = rate/period, n = periods
Investment Growth Over Time
Year-by-Year Breakdown
| Year | Contributions | Earnings | Total Earnings | Balance | Inflation-Adj. |
|---|
Understanding Investment Growth
Future Value with Contributions
FV = P(1+r)^n + PMT x [((1+r)^n - 1) / r]
Combines the future value of a lump sum (P) with the future value of regular contributions (PMT) to calculate total investment growth.
Inflation Adjustment
Real Value = FV / (1 + i)^n
Converts future dollars to today's purchasing power. With 3% inflation, $100 in 20 years is worth about $55 in today's dollars.
Rule of 72
Years to Double = 72 / Interest Rate
Quick estimate for how long it takes to double your money. At 7% returns, money doubles in about 10.3 years.
Frequently Asked Questions
The future value formula for investments with regular contributions is FV = P(1+r)^n + PMT x [((1+r)^n - 1) / r], where P is the initial principal, r is the periodic interest rate, n is the number of periods, and PMT is the regular contribution amount. This formula accounts for both the growth of your initial investment and the compounded growth of regular contributions over time.
When contributions are made at the beginning of each period (annuity due), your money has more time to grow because each contribution earns interest for the full period. End-of-period contributions (ordinary annuity) earn interest starting from the next period. Beginning-of-period contributions typically yield 1-3% more over long time horizons due to the extra compounding time.
Inflation reduces the purchasing power of your money over time. While your nominal investment value may grow significantly, the real (inflation-adjusted) value shows what that money will actually buy in today's dollars. For example, $1 million in 30 years at 3% inflation is worth only about $412,000 in today's purchasing power. Our calculator shows both nominal and inflation-adjusted values.
Historical average returns vary by investment type: US stock market (S&P 500) has averaged about 10% annually, bonds average 5-6%, and savings accounts offer 1-5%. For conservative long-term planning, many advisors suggest using 6-7% for diversified portfolios. Remember that past performance doesn't guarantee future results, and returns fluctuate significantly year to year.
A common guideline is to save 10-15% of your gross income for retirement. The exact amount depends on your age, retirement goals, and current savings. Starting early is crucial due to compound growth - investing $500/month starting at age 25 with 7% returns yields about $1.2 million by 65, while starting at 35 yields only about $567,000. Use this calculator to model different scenarios.