Compound Interest Calculator
Calculate how compound interest grows your money over time with optional regular contributions.
Calculator
Final balance
$81,164.97
Total contributions
$10,000
Interest earned
$71,164.97
Projection
What is compound interest?
Compound interest is interest earned on both your initial principal and the interest that has already accrued. Albert Einstein reportedly called it "the eighth wonder of the world."
Example
$10,000 invested at 7% for 30 years grows to $76,123 without adding another penny.
Money-saving tips
- •Start early — time matters more than the amount you invest.
- •Reinvest dividends and interest to maximize compounding.
- •Even a 1% difference in return compounds dramatically over decades.
Common mistakes
- •Withdrawing gains instead of letting them compound.
- •Underestimating the impact of fees on long-term returns.
Financial definitions
- Principal
- The initial amount of money you invest or save.
- Compounding
- When interest earns interest, accelerating growth over time.
Frequently asked questions
Related calculators
Investment Growth Calculator
Project how your investments grow over time with regular contributions and expected returns.
Savings Growth Calculator
See how your savings grow over time with regular contributions and compound interest.
Investment Return Calculator
Calculate the annualized return (CAGR) of an investment based on starting and ending values.
Dividend Calculator
Estimate dividend income and total return from a dividend-paying stock or portfolio.
Estimated reading time: 5 min