Compound Interest Calculator
Determine how much your money can grow using the power of compound interest.
Your numbers
Your projected balance
How compound interest works
Compound interest is interest earned on both your original deposit and on the interest that deposit has already earned. Each time interest is added to your balance, the next round of interest is calculated on that larger balance - so growth accelerates the longer your money stays invested. Compounding more frequently (daily vs. annually, for example) grows your balance slightly faster for the same nominal interest rate, since interest starts earning its own interest sooner.
FAQ
Does compounding frequency really make a big difference?
Less than most people expect. Moving from annual to daily compounding at the same rate typically changes the final balance by a small amount over most timeframes - the interest rate and how long you leave your money invested matter far more than how often interest compounds.
How is this different from the retirement calculator?
This tool is a general-purpose compound growth calculator - useful for savings accounts, CDs, or any goal with a fixed timeframe. The retirement calculator is built specifically around current age and retirement age. Both use the same underlying math.
What interest rate should I use?
Use the actual rate for savings accounts or CDs (check your bank's current APY). For long-run stock market investments, a common simplified assumption is 6-8% annually, though actual returns vary significantly year to year.
