Compound Interest Calculator
Calculate how your investments grow over time with compound interest.
Investment details
Enter your investment information
1 = annually, 4 = quarterly, 12 = monthly, 365 = daily
Results
Enter investment details and click Calculate
Your results will appear here
About This Compound Interest Calculator
This compound interest calculator helps you estimate how much an investment could grow when interest is added back into the balance and earns more interest over time.
Enter your investment details, including your initial investment, annual interest rate, time period, and how often interest compounds. The calculator then shows your future balance, total interest earned, and year-by-year growth.
Compound interest works best when money is left to grow for a long time. Even small changes in rate, time, or compounding frequency can make a noticeable difference to your final balance.
How to Use This Calculator
- 1
Enter your initial investment
Add the amount you are starting with. This is the base amount that will grow over time.
- 2
Add your annual interest rate
Enter the expected yearly return or interest rate as a percentage.
- 3
Choose the time period
Enter how many years you want the money to grow.
- 4
Set the compounding frequency
Use 1 for annually, 4 for quarterly, 12 for monthly, or 365 for daily compounding.
Frequently Asked Questions
What is compound interest?v
Compound interest is interest earned on both your original investment and the interest already added to it. Over time, this creates growth on top of growth, which is why compound interest can become powerful over long periods.
How often should interest compound?v
The more often interest compounds, the faster your investment can grow. Annual compounding adds interest once per year, quarterly adds it four times per year, monthly adds it twelve times per year, and daily adds it 365 times per year.
What is the difference between compound and simple interest?v
Simple interest is calculated only on your original investment. Compound interest is calculated on your original investment plus previously earned interest, so it usually grows faster over time.
How can I maximize compound interest?v
You can maximize compound interest by starting early, leaving your money invested for longer, using regular contributions, choosing competitive interest rates, and avoiding unnecessary withdrawals.
What is the rule of 72?v
The rule of 72 is a quick way to estimate how long it takes money to double. Divide 72 by your annual interest rate. For example, at 6% interest, money roughly doubles in 12 years.