Ordinary annuity vs annuity due
An ordinary annuity assumes payments happen at the end of each period. An annuity due assumes payments happen at the beginning, giving each payment one extra period to compound. Actual annuity products can include fees, surrender charges, tax treatment and guarantees that are not modeled here.
Example
If you contribute 500 per month for 20 years at a 5% annual return, the total paid in is 120,000. The calculator estimates the future value from those repeated payments and separates the amount you contributed from the estimated growth.
Best use case
Use this page for a transparent compounding estimate of repeated deposits, such as a savings plan or investment contribution schedule. For retirement planning, compare the future value with inflation-adjusted results and withdrawal assumptions.
Common mistakes
Make sure the payment frequency matches how often the payment is actually made. A monthly payment with 12 payments per year is not the same as one annual payment. Also remember that a fixed return assumption is a simplification, not a promise of future performance.
Last reviewed: 2026-05-17