Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Table of how many years it takes to make a specified return on the stock market?
Well depends but "on average" the stock market has historically returned somewhere around 10% per year.  Note, this can vary wildly from year to year see http://en.wikipedia.org/wiki/S%26P_500#Market_statistics So it would be roughly 2.8 years to get your 30% if you happen to get the average market return for those 3 years, but the chances of that happening exactly are slim to none.  You could end up with +50% or -30% over that ~3 year period of time - so the calculation doesn't do you that much good for that short period of time, but if you are talking a span of 30 years then you could plan using that as a very rough ballpark. Good rule of thumb is you shouldn't put any money in the stock market you think you will need anytime in the next 5 years. Formula to figure out total gain would be  Principal x (1+ rate of return) ^ years