Compound Interest Calculator
See how principal grows with compounding interest by year, quarter, month, or day.
Enter the starting principal, the annual interest rate as a percentage, the number of years the money will grow, and how often interest compounds each year. Common choices are annually, quarterly, monthly, or daily.
The calculator applies the compound interest formula to show the final balance, the total interest earned, and the growth multiple compared to the original principal. More frequent compounding leads to slightly higher returns.
This is a simplified projection. It assumes a fixed rate and no additional deposits or withdrawals, which differs from real accounts that may have fees or variable rates.
Frequently asked questions
What is the compound interest formula?
The future balance equals principal times one plus the annual rate divided by compounding frequency, raised to the power of compounding frequency times years.
Does compounding frequency matter much?
Yes, but the effect is usually modest. Daily compounding earns slightly more than monthly, which earns slightly more than annual compounding, because interest starts earning interest sooner.
Can I use this for loans?
This calculator shows growth of savings or investments. For loans, use the loan calculator to see monthly payments and total interest under standard amortization.