====== NPer(rate, payment, curr_val) ======
Category:  Number (Financial) function

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=====Description=====
This function calculates the number of periods for an investment based on periodic payments and interest rate.

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=====Additional syntax=====
Optional //future value// (fut_val) argument.
  nper(rate, payment, curr_val, fut_val)
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Optional //payments due// (pay_due) argument.
  nper(rate, payment, curr_val, fut_val, pay_due)

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=====Arguments=====
^Argument^Type^Description^
|rate|Number (decimal)|The interest rate of the loan (entered as a decimal).|
|payment|Number (negative)|The payment made each period (that does not change), entered as a negative value.  Includes principal\\ and interest, but no fees or taxes.|
|curr_val|Number|The current value of the annuity.|
|fut_val|Number|Optional.  The future value, or cash balance, to be achieved after the last payment (i.e., "0" to pay the loan\\ off in full).  The default, if not supplied, is //0//.|
|pay_due|Binary (0 or 1)|Optional.  This value defines when payments are due.  Options:  //0// (the beginning of the period; default),\\ or //1// (the end of the period).|

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**Return value type:**  Number

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=====Remarks=====
For an accurate calculation, be sure to convert //rate// to the time period desired.  If calculating a monthly rate and //rate// is given as years, divide by 12 (//rate// / 12).

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=====Examples=====
** Calculate the number of monthly periods:**  Interest rate is 12% (annual), payment is $100 per month, current value is -$500, final value is $12,000.
  nper( (0.12/12), -100, -500, 12000) //Returns 74.34 (months, rounded)
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** Calculate the number of monthly periods:**  Interest rate is 2% (monthly), payment is $250 per month, current value is $0, final value is $20,000, payments due at the end of the period.
  nper(0.02, -250, 0, 20000,1) //Returns 47.64  (months, rounded)
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** Calculate the number of yearly periods:**  Interest rate is 12%, payment $7200 per year, current value is $27,000, final value is 0 (paid off).
  nper(0.12, -7200, 27000, 0) //Returns 5.28 (years, rounded)

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===== See also =====
  * [[syntax:functions:fv|FV(rate, num_per, payment)]]
  * [[syntax:functions:ipmt|IPmt(rate, per, num_per, curr_val)]]
  * [[syntax:functions:pmt|Pmt(rate, num_per, curr_val)]]
  * [[syntax:functions:ppmt|PPmt(rate, num_per, curr_val)]]
  * [[syntax:functions:pv|PV(rate, num_per, payment)]]
  * [[syntax:functions:rate|Rate(num_per, payment, curr_val)]]