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Investment Calculator

Calculate investment returns, ROI, CAGR, and compare different investment types. Make informed investment decisions with detailed projections.
Decision Context
Page-specific guidance for using this result in a real planning decision.

Use this page to model projected investment growth, compare scenarios, and estimate how contributions and expected return affect long-term outcomes.

It works well for portfolio planning, target-balance checks, and evaluating whether your current savings pace can realistically support a future goal.

Results should be read as scenario analysis, not guaranteed performance, because investment returns are uneven and real-world taxes, fees, and sequence risk can change the path materially.

Methodology, assumptions, and limitations

Projected value is calculated from starting capital, recurring contributions, time, and an assumed annual return. The result is a scenario projection rather than a forecast of a specific security or portfolio.

Assumptions
  • Contributions and the assumed return follow the selected schedule.
  • Returns are represented by a smooth average.
  • Withdrawals are excluded unless explicitly entered.
Limitations
  • Sequence-of-returns risk is hidden by a constant average return.
  • Taxes, trading costs, and fund fees can reduce results.
  • No projected return is guaranteed.

Sources and standards

Related calculators

Compound Interest CalculatorRetirement Calculator
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Analysis
Interpretation of the current calculator output

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How to Use

Step-by-step instructions
  1. 1Enter your initial investment amount (principal)
  2. 2Input your expected annual return rate as a percentage
  3. 3Select your investment time period in years
  4. 4Add any regular monthly contributions to your investment
  5. 5Choose an investment type to see risk and return comparisons
  6. 6Review the growth projections and compare different scenarios

Compound Interest Formula

This formula calculates the future value of an investment with compound interest and regular contributions.
A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]

Variables:

AFuture value of the investment
PPrincipal (initial investment)
rAnnual interest rate (as a decimal)
nNumber of times interest compounds per year
tNumber of years
PMTRegular payment contribution amount

Example

Calculating Investment Growth with Monthly Contributions

Inputs:

Initial Investment:$10,000
Monthly Contribution:$500
Annual Return:8%
Time Period:20 years

Steps:

  1. 1.Convert annual rate to monthly: 8% ÷ 12 = 0.6667% or 0.006667
  2. 2.Calculate total periods: 20 years × 12 = 240 months
  3. 3.Apply compound interest formula with contributions
  4. 4.Future value = 10,000 × (1 + 0.006667)^240 + 500 × [((1 + 0.006667)^240 - 1) / 0.006667]
  5. 5.Calculate: Future value = 10,000 × 4.9268 + 500 × 554.27
  6. 6.Result: Future value = $326,403
Result:
Future Value: $326,403 | Total Contributions: $130,000 | Total Earnings: $196,403 | ROI: 151.1%

Frequently Asked Questions

How accurate are these investment projections?

These calculations provide estimates based on assumed rates of return. Actual investment performance will vary due to market fluctuations, fees, taxes, and other factors.

Should I invest a lump sum or contribute regularly?

Regular contributions through dollar-cost averaging can reduce the impact of market volatility. Lump sum investing may provide higher returns if the market trends upward, but comes with higher risk.

How does inflation affect my investment returns?

Inflation reduces the purchasing power of your money over time. To maintain real growth, your investments should earn returns that exceed the inflation rate.

What is a realistic expected return for long-term investments?

Historically, the stock market has returned about 10% annually, while bonds have returned about 5-6%. A diversified portfolio might expect 7-8% annual returns after adjusting for inflation.