Free Online Compound Interest Calculator
Calculate how much your savings or investment will grow over time with compound interest. Enter your principal, interest rate, term, and compounding frequency to see your future value.
How to Use the Interest Calculator
1. Enter Your Principal
The starting amount you are investing or saving.
2. Set Your Interest Rate and Term
Your annual interest rate (APY) and how many years you plan to leave the money invested.
3. Choose Compounding Frequency
More frequent compounding means faster growth. Daily compounding grows slightly faster than annual compounding.
4. View Your Future Value
See how much your money grows, including the total interest earned.
Understanding Compound Interest
Compound interest is calculated using the formula:
Where A is the future value, P is the principal, r is the annual interest rate, n is the number of compounding periods per year, and t is the time in years.
Unlike simple interest (which only earns interest on the principal), compound interest earns interest on both the principal and previously earned interest — the "interest on interest" effect that accelerates long-term growth.