Overview
Enter a starting principal, an annual interest rate, a time period in years, and how often interest compounds - daily, monthly, quarterly, semi-annually, or annually - to calculate the future value: A = P × (1 + r/n)^(n × t), where P is the principal, r is the annual rate as a decimal, n is the number of compounding periods per year, and t is the number of years. This is a general-purpose version of the same compounding math behind this site's CD Calculator, meant for any savings or investment scenario rather than a Certificate of Deposit specifically - a general brokerage account, a high-yield savings account, or a classroom compound-interest problem. Both the projected future value and the total interest earned (future value minus principal) are shown, along with the formula worked out with your actual numbers. Runs entirely client-side, and this is an informational estimate, not financial advice.
Best for: Projecting how much a savings or investment balance will grow over time at a given interest rate
How to use this tool
- Enter the principal, rate, and time period. The starting amount, the annual interest rate, and how many years it will grow for.
- Choose a compounding frequency. Daily, monthly, quarterly, semi-annually, or annually.
- Read the future value. The projected ending balance and the total interest earned, using A = P × (1 + r/n)^(n × t).
Frequently asked questions
They share the exact same underlying compounding formula, but the CD Calculator is framed specifically around Certificates of Deposit - it labels the input a "deposit" and warns about APR versus APY conventions specific to CDs. This calculator uses general savings/investment language (principal, rate, future value) for any compounding scenario, not just a CD.
It changes n, the number of times per year interest is calculated and added to the balance. More frequent compounding (daily versus annually, for example) means interest starts earning its own interest sooner, which produces a slightly higher future value for the same nominal annual rate.
No - this models a single lump-sum principal compounding over time with no additional deposits or withdrawals. If you're adding money regularly, the actual future value will be higher than what this tool shows, since it doesn't account for those extra contributions.