NPER Function

NPER.js

// Copyright (c) 2012 Sutoiku, Inc. (MIT License)

function NPER(rate, payment, present, future, type) {
  // Initialize type
  var type = (typeof type === 'undefined') ? 0 : type;

  // Initialize future value
  var future = (typeof future === 'undefined') ? 0 : future;

  // Evaluate rate and periods (TODO: replace with secure expression evaluator)
  rate = eval(rate);

  // Return number of periods
  var num = payment * (1 + rate * type) - future * rate;
  var den = (present * rate + payment * (1 + rate * type));
  return Math.log(num / den) / Math.log(1 + rate);
}

Doesn't seem to work when rate is 0

thanks man your a life saver

try passing

NPER(0/12, 200, -3000, 0)
this function fails

i have rate: 3.25% ,payment:5000,present:150000,
why does it return a negative value . How can i get no of months from this or the amount with interest