Compound Interest Calculator
Compound interest is interest earned on interest already earned. Enter a starting balance, a monthly contribution and a rate to see how the balance grows and how much of the final figure is interest rather than deposits.
$
$
%
yrs
Balance after 10 years
$53,469
- Total deposited
- $40,000
- Interest earned
- $13,469
Assumes the rate holds for the whole period and contributions are made at the end of each month.
Frequently asked questions
- How does compounding frequency change the result?
- More frequent compounding produces a slightly higher balance because interest starts earning interest sooner. At the same nominal rate, daily compounding beats annual compounding by a small margin that grows with time and balance.
- What is the difference between interest rate and APY?
- The interest rate is the nominal annual rate. APY folds in the effect of compounding, so it is always equal to or higher than the nominal rate. When comparing two savings accounts, compare APY.