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Investment Return Calculator Project future investment value with initial investment and regular monthly contributions.

Investment Return Calculator illustration
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Investment Return Calculator

Project future investment value with initial investment and regular monthly contributions.

1

Enter Initial Investment

Input your starting investment amount.

2

Set Contributions & Rate

Enter monthly contribution amount and expected annual return.

3

View Projection

See future value, total contributed, growth earned, and year-by-year milestones.

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What Is Investment Return Calculator?

An investment return calculator projects the future value of your investments based on an initial lump sum, regular monthly contributions, expected annual return rate, and time horizon. It combines the power of compound growth on your initial investment with the consistent accumulation of new contributions, showing how both work together to build wealth over time. The calculator displays the split between money you contributed and money earned through growth, often revealing that compound growth accounts for the majority of your final balance in long-term scenarios. Year-by-year milestones show the accelerating nature of compound growth — the balance grows faster each year because the growth base keeps increasing.

Why Use Investment Return Calculator?

  • Combines initial investment with regular contributions
  • Year-by-year growth milestones table
  • Visual breakdown of contributions vs investment growth
  • Shows the power of long-term compounding
  • Adjustable for different scenarios and return assumptions

Common Use Cases

Long-Term Investing

Project how index fund or ETF investments grow over decades.

Savings Planning

See how regular monthly savings compound into significant wealth.

Goal Setting

Determine how much to invest monthly to reach a financial target.

Retirement Planning

Estimate portfolio value at retirement based on current saving rate.

Technical Guide

The future value combines two components: (1) FV of initial investment: FV₁ = P × (1 + r)^n, where r is the monthly rate and n is months. (2) FV of monthly contributions (annuity): FV₂ = PMT × ((1 + r)^n − 1) / r. Total FV = FV₁ + FV₂. The year-by-year table is computed iteratively: each month, balance = balance × (1 + r) + PMT. Historical average returns: US stocks ~10% nominal (~7% real after inflation), bonds ~5%, savings ~2-4%. The calculator does not account for inflation, taxes, or variable returns. In reality, returns fluctuate significantly year to year — the projected growth assumes a steady rate for simplicity.

Tips & Best Practices

  • 1
    Historical S&P 500 average return: ~10% nominal, ~7% after inflation
  • 2
    Regular contributions matter more early in your investing career
  • 3
    Don't forget that returns are variable — these projections use constant rates
  • 4
    Consider using 7% instead of 10% for inflation-adjusted projections
  • 5
    Tax-advantaged accounts (401k, IRA) let your investments grow without annual tax drag

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Frequently Asked Questions

Q What return rate should I use?
Historical averages: US stocks ~10%/year (nominal), bonds ~5%, savings ~2-4%. Use 7% for inflation-adjusted projections. Conservative planning might use 6-8%.
Q Does this account for inflation?
No. To see inflation-adjusted values, subtract the inflation rate (~3%) from your expected return rate.
Q How important are monthly contributions?
Very important. For a 30-year horizon, monthly contributions often contribute more to the final balance than the initial investment, especially with compound growth.
Q Are investment returns guaranteed?
No. This calculator uses a constant assumed return. Actual returns vary significantly year to year. Diversification helps manage risk but doesn't eliminate it.
Q Does this include taxes?
No. Investment returns are shown pre-tax. Actual returns depend on account type (taxable, IRA, 401k), holding period, and your tax bracket.

About This Tool

Investment Return Calculator is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.