Compound Interest Calculator
Project the future value of your savings or investments with compounding and regular deposits.
How to use: Enter your starting amount, regular deposits, interest rate and number of years to see how your money grows.
How to use the Compound Interest Calculator
Compound interest means you earn interest on your original money and on the interest it has already earned. Over long periods this snowball effect becomes powerful, which is why starting early matters more than almost any other investing habit.
Enter a starting balance, a monthly deposit and an expected annual rate of return. Pick how often interest compounds: daily and monthly compounding give slightly higher results than annual compounding at the same rate. Then choose how many years you want to project.
The results show the final balance, your total deposits and the interest earned. The table below breaks the growth down year by year so you can see when interest begins to outpace your own contributions.
Remember that real investment returns are not guaranteed and vary from year to year. Use a conservative rate for planning, and consider the effect of inflation and taxes, which this calculator does not include. For a view that accounts for rising prices, pair it with the inflation calculator.
Frequently asked questions
What is the compound interest formula?
The core formula is A = P(1 + r/n)^(nt), where P is the principal, r the annual rate, n the compounding periods per year and t the years. Regular deposits are added on top of this growth.
Is daily compounding much better than monthly?
The difference is small. Moving from annual to monthly compounding matters more than moving from monthly to daily.
Can I use it for debt?
Yes. Credit cards and some loans compound too, so you can set the starting balance to your debt and the monthly deposit to zero to see how fast it grows.