Use this free compound interest calculator to estimate how your money can grow over time. Enter your starting amount, monthly contribution, interest rate, and time horizon to see your projected future value, total contributions, and interest earned.
This calculator is useful for modeling savings accounts, certificates of deposit (CDs), retirement contributions, and long-term investing scenarios.
This calculator is for informational purposes only and assumes a constant interest rate, regular contributions, and no taxes or fees.
Compound interest means you earn interest not only on your original deposit, but also on the interest that has already been added to your balance.
Over long periods of time, compounding can significantly increase the value of your savings, especially when combined with regular monthly contributions.
The earlier you start, the more time your money has to grow. Even relatively small monthly deposits can build into a meaningful balance over many years.
Read more here: What is compound interest?
This calculator combines your starting balance, ongoing monthly contributions, annual interest rate, and compounding frequency to estimate your ending balance.
A = P(1 + r / n)^(nt)
Because this tool also includes recurring monthly contributions, it applies the growth repeatedly across each compounding period rather than using only the simplest one-time deposit formula.
Certificates of deposit, or CDs, are savings products that usually offer a fixed interest rate for a set term. They can be useful when you want predictable returns and do not need immediate access to your funds.
This calculator can help you estimate how a CD balance might grow over time, especially when comparing different rates and time periods.
Learn more here: What is a CD?
Monthly compounding means interest is added to your balance 12 times per year. Each new month, you earn interest on both your original money and previously earned interest.
Yes. You can enter a monthly contribution amount and the calculator will include those deposits in the projected ending balance.
It is useful for planning and estimation, but real-world returns can vary. Actual savings or investment performance may differ because of taxes, fees, changing interest rates, or market conditions.
Compound interest allows savings and investments to grow not only from the original deposit, but also from previously earned interest. Over long periods of time, this compounding effect can significantly increase total growth.
That depends on what you are modeling. A high-yield savings account, CD, index fund, or retirement account may all have different expected returns. Many people test several rates to compare conservative and optimistic scenarios.
Explore additional calculators and financial utility tools: