PMT

Returns a Double specifying the payment for an annuity based on periodic, fixed payments and a fixed interest rate.

Function Pmt( _

ByVal Rate As Double, _

ByVal NPer As Double, _

ByVal PV As Double, _

Optional ByVal FV As Double = 0, _

Optional ByVal Due As DueDate = DueDate.EndOfPeriod _

) As Double

Rate

Required. Double specifying interest rate per period. For example, if you get a car loan at an annual percentage rate (APR) of 10 percent and make monthly payments, the rate per period is 0.1/12, or 0.0083.

NPer

Required. Double specifying total number of payment periods in the annuity. For example, if you make monthly payments on a four-year car loan, your loan has a total of 4 * 12 (or 48) payment periods.

PV

Required. Double specifying present value (or lump sum) that a series of payments to be paid in the future is worth now. For example, when you borrow money to buy a car, the loan amount is the present value to the lender of the monthly car payments you will make.

FV

Optional. Double specifying future value or cash balance you want after you've made the final payment. For example, the future value of a loan is $0 because that's its value after the final payment. However, if you want to save $50,000 over 18 years for your child's education, then $50,000 is the future value. If omitted, 0 is assumed.

Due

Optional. Object of type Microsoft.VisualBasic.DueDate that specifies when payments are due. This argument must be either DueDate.EndOfPeriod if payments are due at the end of the payment period, or DueDate.BegOfPeriod if payments are due at the beginning of the period. If omitted, DueDate.EndOfPeriod is assumed.

http://msdn.microsoft.com/en-us/library/hyd90ysd%28v=vs.71%29.aspx