• cnper(rate, pv, fv)—Returns the number of compounding periods for an investment to yield a specified future value fv, given a specific rate and present value pv.
• nper(rate, pmt, pv, [[fv], [type]])—Returns the number of periods for an investment or loan based on periodic, constant payments pmt using a fixed interest rate and a specified present value pv.
Arguments
• rate is the real, positive, scalar fixed interest rate per period. Typically, 0 ≤ rate < 1.
• pv is the real, positive present (or initial) value loan.
• fv (optional for nper) is the future value: a cash balance you want to attain after the last payment is made. If omitted, fv = 0.
• pmt is the real payment made each period. It usually includes principal and interest but no other taxes and fees.
If pmt > 0, rate and pv must be of opposite signs.
• type (optional) is 0 for a payment made at the end of the period or 1 for the beginning. If omitted, type = 0.