(1) Enter the cost of an item you wish to purchase.
(2) Enter the annual percentage increase in cost for the item(usually 3%).
(3) Enter number of years you wish to set aside for saving.
(4) Enter your tax rate.
(5) Expected annual return on the short-term investment you've chosen.
(6) Lump-sum amount that you can set aside now.
(7) Choose a monthly savings factor from the chart below.