🧮 Calculators
Compound Interest Calculator
See how your investments grow with compound interest. Add monthly contributions and see year-by-year projections. All calculations run in your browser.
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Your Investment Growth
Final Amount
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Total Contributions
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Interest Earned
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Growth Multiple
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How it works
01
Enter Details
Your starting amount, interest rate, and time period.
02
Add Contributions
Optionally add monthly deposits to grow faster.
03
See Growth
Get final amount, total interest, and yearly chart.
Frequently asked questions
What is compound interest?
Compound interest means you earn interest on your interest. Each period, the interest gets added to your balance, so next period you earn interest on a larger amount. Over years, this creates exponential growth.
Which compounding frequency should I choose?
Most savings accounts compound monthly or daily. Bonds and CDs may compound quarterly or annually. Check with your bank or investment provider.
How is compound interest calculated?
Formula: A = P(1 + r/n)^(nt), where P is principal, r is annual rate, n is compounding periods per year, and t is years. With contributions, we add each deposit and compound from that point forward.
Is this a real-time calculation?
Yes, all math runs in your browser instantly. No data is sent anywhere.
All tools are free, browser-based, and process files locally — your data never leaves your device.
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