Compound Interest Calculator
Interest & SavingsSee how your savings or investments grow over time with compound interest. Adjust compounding frequency to compare scenarios.
Growth Summary
Future value
$46,146
after 10 years
Total interest earned
$17,146
Total contributions
$24,000
Effective annual rate
7.763%
What is a Compound Interest Calculator?
A compound interest calculator shows you the remarkable power of letting your money grow on itself over time. Unlike simple interest, compound interest earns returns on both your original principal and the interest already accumulated — making it the engine behind long-term wealth building in [GEO] and everywhere else.
How to use this calculator
Enter your initial deposit, optional monthly contributions, annual interest rate, the compounding frequency, and the investment period. The calculator shows your final balance, total interest earned, and a year-by-year breakdown of how your money grows. A visual bar shows what portion of your final balance is original deposit versus earned interest.
Example
$10,000 invested at 8% compounded monthly for 10 years, with $100 added monthly, grows to approximately $26,765. Of that, $12,000 is your total deposits and $14,765 is pure interest — more than your original investment.
Frequently asked questions
What is the difference between APR and APY?
APR (Annual Percentage Rate) is the stated interest rate. APY (Annual Percentage Yield) accounts for compounding frequency — it shows your actual effective return. More frequent compounding means a higher APY than APR.
How often should interest compound?
The more frequently interest compounds, the faster your money grows. Daily compounding yields slightly more than monthly, which yields more than annually. For most savings accounts, monthly compounding is standard.
What is the Rule of 72?
Divide 72 by your annual interest rate to estimate how many years it takes to double your money. At 8% annual return, your investment doubles roughly every 9 years (72 ÷ 8 = 9).
Does compound interest work against me on debt?
Yes — compound interest works for you on investments but against you on debt. Credit cards and loans compound interest on your balance, which is why carrying debt is expensive.