The Motley Fool Discussion Boards Previous Page Investing/Strategies / Retirement Investing URL:  http://boards.fool.com/2nd-and-the-one-that-i-am-trying-to-find-a-16886941.aspx Subject:  Re: Formula to Calculate Growth Date:  3/13/2002  4:53 AM Author:  ptheland Number:  33986 of 88543 2nd) (and the one that I am trying to find a formula for) Suppose that I start an IRA with an initial investment of \$1000 and every year I add \$3000 more to it. What formula can I use to determine how much the IRA will be worth in a certain number of years given an expected rate of return. You're looking for the future value of an annuity, which gets a little messier. One formula is:`((1+r)^n) - 1------------- r`where r is the expected rate of return (per period) and n is the number of periods.That will work for the \$3000 annual additions. Then you'll need to add in the value of your initial contribution of \$1000 figured from the formula given to you earlier.--Peter Copyright 1996-2018 trademark and the "Fool" logo is a trademark of The Motley Fool, Inc. Contact Us