Investment Growth Calculator

Use this free calculator to estimate how your investments could grow over time through compound interest and recurring contributions. Get clear projections, breakdown charts, and a detailed growth schedule.

Read our guide on how to use this calculator ↓

Projected Results

End Balance$0.00
Starting Amount$0.00
Total Contributions$0.00
Total Interest$0.00

Monthly Schedule

How to Use the Investment Growth Calculator

This free Investment Growth Calculator helps you estimate how much your money could grow over time based on your starting balance, contribution schedule, and expected rate of return. It uses a realistic compound interest model to show how your wealth can build month by month.

Input Fields Explained

Each input affects your results in a specific way. Here’s what each one means:

💰 Starting Amount ($)

This is your initial investment balance — the amount of money you already have saved or invested. If you’re starting from zero, simply enter 0.

📅 Planned Investment Length (Years)

Enter the total number of years you plan to keep the investment growing. This represents your time horizon — and it’s one of the most powerful factors in compound growth. The longer you invest, the more your interest earns interest.

📈 Expected Annual Return Rate (%)

This is the average annual return you expect to earn. The calculator treats this as an APR (Annual Percentage Rate) and compounds it monthly to simulate real-world growth. Historically, diversified stock market returns average between 6% and 10% annually, but you can adjust this based on your investment strategy.

➕ Additional Contributions

This setting controls how much new money you add over time:

Regular contributions significantly boost growth by allowing more money to benefit from compounding earlier.

Understanding Your Results

Once you calculate your projection, you’ll see a detailed breakdown of your investment over time. The calculator provides total contributions, interest earned, and ending balance — plus two visual charts to help you interpret your growth.

📊 Stacked Bar Chart — Investment Growth Over Time

This chart shows your total investment value each year, broken down into contributions and interest earned. Watch how the interest portion grows faster in later years — that’s the magic of compound interest at work.

🥧 Pie Chart — Final Balance Breakdown

The pie chart gives a clear visual of your ending balance, showing what percentage comes from:

In most long-term investment scenarios, you’ll notice that earned interest becomes the largest share of your total — demonstrating the exponential power of compounding.

Tips for Using This Calculator Effectively

Related Tools & Resources

Explore more financial calculators: Compound Interest Calculator, Retirement Savings Calculator, and Future Value Calculator.


Frequently Asked Questions (FAQs)

What does an investment growth calculator do?

An investment growth calculator estimates how your money could grow over time using compound interest. It factors in your starting balance, contribution schedule, time horizon, and expected rate of return to project your future balance.

How accurate are investment growth calculators?

While calculators use mathematical formulas for compound interest, actual investment returns vary. This tool provides an estimate based on your inputs — market performance and fees can impact real results.

What’s a good average annual return to use?

A conservative long-term assumption is 6–7% for diversified investments. Historically, the U.S. stock market (S&P 500) has averaged around 10% before inflation.

How can I grow my investments faster?

You can increase your growth potential by investing regularly, starting early, and keeping investments long-term. The more time your money has to compound, the larger your future balance.