Examples
Suppose that you put $1000 per month into a retirement savings plan that pays 6 percent annual interest, compounded monthly. How much will the account be worth after 20 years?
FV (0.06 / 12, 20 * 12, -1000)
Returns 462041 (rounded to the nearest integer). So your account will have $462,041. The payment (-1000) is negative since you are paying out the money to the plan.
The above example assumes that you made your payments into the plan at the end of the month. Thus after the first month, your plan would have only $1000 in it, since there was no time for interest to accrue. Suppose that instead you make your payments at the start of the month:
FV (0.06 / 12, 20 * 12, -1000, 0, 1)
Returns 464351 (rounded to the nearest integer). So your account will have $464,351. You will save $2,310 more by depositing at the beginning of the month.
Now suppose that in addition to making payments at the start of the month, you start your plan with an initial deposit of $20,000.
FV (0.06 / 12, 20 * 12, -1000, -20000, 1)
Returns 530555 (rounded to the nearest integer). Your account will have $530,555 after 20 years.
You can also use the FV function to calculate the future value of a lump sum deposit. For example, if you deposit $20,000 in to a plan that pays 6 percent annual interest compounded monthly for 20 years:
FV (0.06 / 12, 20 * 12, 0, -20000)
Returns 66204 (rounded to the nearest integer). Thus you would have $66,204 in your account. This is also equal to the difference of the previous 2 examples ($530,555 - $464,351).