Calculates the number of periods necessary for a recurring investment based on an interest rate, the amount of payment per period, a present value, a future value and either ordinary annuity or annuity due (type) indicating whether payments are due at the beginning or the end of period.
NPER('Rate', 'Pmt', 'Pv' [, 'Fv' [, "Type"]])
In case the costs or payments are entered as a positive number within your model, this function needs to be multiplied by (-1).
(Payment per Period - Amount)
Payment at Beginning of Period (Annuity Due) = 1
Payment at End of Period (Ordinary Annuity) = 0
NPER(Rate, Pmt, Pv, Fv, Type)