Annuity Calculator — Future Value of Regular Payments
An annuity is a series of equal payments made at regular intervals. Enter the payment amount, annual interest rate, investment term and payment frequency to find the future value — the total pot your contributions grow to — and see how much of that total is interest versus your own deposits.
%
yrs
Payment frequency
Annuity type
Total accumulated value after all payments and interest
- 1
Periodic interest rate
6% ÷ 100 ÷ 12 = 0.005 - 2
Total periods
20 yrs × 12 = 240 - 3
Growth factor
(1 + 0.005) ^ 240 = 3.3102Compound growth of one unit over the full term. - 4
Future value
500 × (3.3102 − 1) ÷ 0.005 = 231,020.45
How does this calculator work?
FV = PMT × [(1 + r)^n − 1] / r, where r is the periodic rate (annual ÷ periods/year) and n is total periods. Saving $500/month at 6%/year for 20 years grows to about $231,020 — $120,000 of your contributions and $111,020 of interest. An annuity due (payments at start) multiplies the result by (1 + r) for one extra compounding period.
Formula
How this is calculated
An ordinary annuity assumes each payment is made at the end of the period. Each payment is then invested and earns compound interest for the remaining periods. The future value formula FV = PMT × [(1 + r)^n − 1] / r sums this geometric series, where PMT is the periodic payment, r is the periodic interest rate (annual rate ÷ compounding periods per year) and n is the total number of periods.
An annuity due shifts each payment to the beginning of the period, giving every payment one extra compounding period of growth. The formula is the same, multiplied by (1 + r). For most retirement accounts and savings plans you will use the ordinary annuity. Annuity due applies when leases or insurance premiums are paid upfront.
The growth curve shows the power of compounding: early on the balance rises slowly (mostly your own contributions); later it accelerates as interest compounds on an ever-larger balance. The longer the term and the higher the rate, the greater the proportion of the final pot that comes from interest rather than your own deposits.
Frequently asked questions
An ordinary annuity pays at the end of each period (most savings plans, mortgages). An annuity due pays at the beginning, so each payment compounds for one extra period. For the same PMT, rate and term, an annuity due always produces a higher future value — by a factor of (1 + r).
Enter your monthly contribution as the payment, your expected annual return as the rate, and the years until retirement. Choose "Monthly" frequency and "Ordinary" type for most employer plans. The result shows how much your nest egg could grow — note that actual returns vary and this is a projection, not a guarantee.
No — the future value shown is a nominal amount in today's dollars of purchasing power only if you use a real (inflation-adjusted) interest rate. To do that, replace the nominal rate with the real rate ≈ (nominal − inflation) / (1 + inflation). For a simple illustration, try a 4% rate if you expect 7% nominal and 3% inflation.
Also known as
TG we-Calculate Editorial Team. (2026). Annuity Calculator — Future Value of Regular Payments [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/annuity-calculator
TG we-Calculate Editorial Team. "Annuity Calculator — Future Value of Regular Payments." TG we-Calculate. 2026. https://we-calculate.com/calculator/annuity-calculator.
TG we-Calculate Editorial Team, "Annuity Calculator — Future Value of Regular Payments," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/annuity-calculator
@misc{wecalculate_annuity_calculator, title = {Annuity Calculator — Future Value of Regular Payments}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/annuity-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?