Investment Calculator

Finance

Last updated: July 11, 2026

Calculate the future value of your investments with compound growth and regular contributions. See how your money can grow over time with different compounding frequencies.

Initial Investment ($)

Monthly Contribution ($)

Annual Return (%)

Investment Period (years)

Compounding Frequency

How to Use This Calculator

Enter your Initial Investment amount or start with $0.
Set the Monthly Contribution you plan to add regularly.
Enter the expected Annual Return rate and Investment Period.
Choose the Compounding Frequency that matches your investment type.
Click Calculate to see future value, total interest, and a year-by-year growth table.

Formula

FV = P × (1 + r/n)^nt + PMT × [((1 + r/n)^nt − 1) / (r/n)]

Where FV = future value, P = initial investment, PMT = monthly contribution, r = annual interest rate (decimal), n = compounding frequency per year, t = investment period in years.

Examples

Index Fund Investor: $10,000 initial, $500/month at 8% for 20 years compounded monthly = $305,797 future value. You invest $130,000 and earn $175,797 in interest.

Long-Term Growth: $25,000 initial, $1,000/month at 9% for 30 years = $2,047,113. Your $385,000 in contributions grow to over $2 million.

Conservative Portfolio: $5,000 initial, $300/month at 5% for 15 years = $95,641. Lower returns but still significant growth on $59,000 invested.

Frequently Asked Questions

What is compound interest?

Compound interest is interest earned on both your original investment and on previously accumulated interest. This creates exponential growth, making it one of the most powerful wealth-building tools over time.

What is the Rule of 72?

The Rule of 72 estimates how long it takes your investment to double. Divide 72 by your annual return rate. For example, at 8% return, your money doubles in approximately 72 / 8 = 9 years.

What is the average stock market return?

The S&P 500 has historically returned about 10% annually before inflation (approximately 7% after inflation). Past performance does not guarantee future results.

How does compounding frequency affect returns?

More frequent compounding means interest is calculated and added to your balance more often, leading to slightly higher returns. The difference is small annually but significant over decades.