Compound Interest Calculator
Calculate how your investments grow over time with compound interest. Enter your principal amount, interest rate, time period, and compounding frequency to see your potential returns.
Enter investment details and click Calculate
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What is Compound Interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Often called "interest on interest," it causes your wealth to grow at an accelerating rate. Albert Einstein reportedly called it "the eighth wonder of the world."
The Compound Interest Formula
The formula for compound interest is:
A = P(1 + r/n)^(nt)
Where A is the final amount, P is the principal, r is the annual interest rate (as a decimal), n is the number of times interest is compounded per year, and t is the number of years. The more frequently interest compounds, the more you earn.
Compounding Frequencies Explained
Annually (n=1)
Interest is calculated and added once per year.
Semi-Annually (n=2)
Interest is calculated and added twice per year.
Quarterly (n=4)
Interest is calculated and added four times per year.
Monthly (n=12)
Interest is calculated and added twelve times per year. Most common for savings accounts.
Daily (n=365)
Interest is calculated and added every day. Provides the highest returns for the same rate.
Maximizing Your Investment Growth
- Start investing early to take advantage of compound growth over time
- Choose investments with more frequent compounding when possible
- Reinvest dividends and interest to accelerate growth
- Make regular contributions to increase your principal
- Be patient - compound interest works best over long time periods
- Consider tax-advantaged accounts like IRAs and 401(k)s
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