Future Value of Annuity Calculator
Explore equal periodic savings contributions under a stated hypothetical return.
How the result changes
Only end-of-period contribution changes; all other inputs stay at your current values. The line illustrates the formula across the shown range. This is not a forecast of real-world outcomes.
About this calculation
Future Value of Annuity Calculator calculates future value from end-of-period contribution, return per period, number of periods. Explore equal periodic savings contributions under a stated hypothetical return. The main answer uses currency units and follows the specific assumptions explained below.
Formula
Future value = contribution × [((1 + periodic rate)^periods − 1) ÷ periodic rate].
Worked example
With End-of-period contribution: 500 currency units, Return per period: 0.5 %, Number of periods: 120, future value is 81,939.67 currency units.
Inputs and calculation
Treat each equal contribution as arriving at the end of its period. Earlier contributions compound for more periods than later ones, giving the geometric-series expression in the formula. The displayed relationship is Future value = contribution × [((1 + periodic rate)^periods − 1) ÷ periodic rate]. Keep the fields' displayed units attached when reproducing this relationship by hand.
Worked numerical example
For example, enter end-of-period contribution 500 currency units, return per period 0.5 %, number of periods 120. Those inputs produce future value of 81,939.67 currency units. The same values also give total contributed 60,000 currency units; modeled growth 21,939.67 currency units.
Holding the other example values fixed, change end-of-period contribution from 500 to 550 currency units. The main output becomes 90,133.64 currency units. This comparison isolates the effect of that one input.
How to read and use the result
The displayed future value is a nominal projection; the contribution total isolates money deposited so the difference can be read as modeled growth. No result is guaranteed. Explore equal periodic savings contributions under a stated hypothetical return.
Practical context
The default uses 120 periods and a 0.5% return per period. If those are months, they describe ten years at a monthly rate, not 120 years or a 0.5% annual rate.
Assumptions and scope
Rate and contribution interval match exactly: a monthly payment needs a monthly rate and a month count. A zero rate gives contributions times periods. Tax, fees and inflation are excluded. Replace the example defaults with measured inputs for your situation and account separately for factors outside these fields.
Checks and common mistakes
Do not enter an annual percentage as though it applied every month. Payments at the beginning of each period require an annuity-due formula and produce a different result.
Common questions
What should I verify before using the Future Value of Annuity Calculator result?
Contributions total 60,000, while the modeled future value is higher because early payments earn more periods of growth. At a zero rate, future value equals the contributed total exactly. An ordinary annuity pays at each period's end; deposits made at the beginning would each gain one additional compounding period.
Sources and references
Inputs
- End-of-period contribution (currency units)
- Return per period (%)
- Number of periods