Compound Interest Calculator
Calculate how your investment grows over time with compound interest and regular contributions. See year-by-year growth and total interest earned.
How to Use This Calculator
- Enter your Initial Investment amount.
- Set the Annual Interest Rate and Years you plan to invest.
- Choose the Compounding frequency (annually, quarterly, monthly, or daily).
- Add an optional Monthly Contribution to see how regular deposits boost growth.
- Click Calculate to view your future value, total interest, and year-by-year breakdown.
Formula
Where FV = future value, P = principal, r = annual interest rate (decimal), n = compounding frequency per year, t = years, and PMT = regular contribution.
Examples
Frequently Asked Questions
How is compound interest different from simple interest?
Simple interest is calculated only on the principal. Compound interest is calculated on the principal plus accumulated interest, so your money grows exponentially over time.
Does compounding frequency matter?
Yes. More frequent compounding (monthly vs. annual) yields slightly more interest. The difference becomes significant over long time periods.
What interest rate should I expect?
A typical high-yield savings account offers 4–5%, while stock market index funds historically average 7–10% annually over the long term.
Should I include inflation?
For long-term planning, consider the real return rate (nominal rate minus inflation) to understand actual purchasing power growth.