What this means
Start with a habit you can keep
Enter an initial deposit and a realistic monthly contribution. Then try a longer saving period before increasing the assumed rate. More time lets earlier deposits earn interest for longer.
Interest on your interest
Compounding adds earned interest to your balance, so future interest is calculated on a larger amount. The frequency controls how often the nominal annual rate compounds. It is separate from how often you contribute.
A projection, not a promise
This model holds the rate constant. Actual investments can lose value, returns vary, and fees and taxes reduce what you keep. Use different rates to explore scenarios rather than treating one result as a forecast.
Good questions
Is the annual rate the same as APY?
No. Enter a nominal annual rate. The effective annual yield is (1 + rate ÷ periods) raised to the number of periods, minus 1. For an APY input, select annual compounding.
Can I compare saving with and without monthly deposits?
Yes. Set the monthly contribution to zero to isolate the growth of your initial deposit. The comparison uses identical cash flows for both interest methods.