Compound Interest Calculator — $10.000 at 7% for 10 Years
Calculate compound interest with monthly contributions. See how your investments grow over time.
Inputs
Starting amount you're investing
Amount you'll add each month
Expected annual return percentage
Investment time horizon
How to Use These Results
- Adjust contributions strategically: Explore how increasing the monthly contribution shortens the time it takes for interest to outpace principal. Even small additions compound dramatically.
- Schedule annual check-ins: Revisit this scenario with updated balances and rates to ensure your investment plan keeps pace with goals and market conditions.
- Consider inflation impacts: Once you lock in a target future value, review it with the Real Return Calculator to see the inflation-adjusted purchasing power.
Frequently Asked Questions
How is compound interest calculated?
Compound interest is calculated by applying the interest rate to both the initial principal and the accumulated interest from previous periods. The formula is A = P(1 + r/n)^(nt), where A is the final amount, P is principal, r is annual rate, n is compounding frequency, and t is time in years.
Can I reinvest monthly contributions?
Yes, monthly contributions are automatically reinvested and compound along with your initial investment. This accelerates growth compared to investing only a lump sum.
What is the difference between simple and compound interest?
Simple interest is calculated only on the principal amount, while compound interest is calculated on the principal plus previously earned interest, leading to exponential growth over time.