How to calculate rate of return?

[Gardening Grandma]

I've seen a formula posted, but can't find it. It had to do with taking the amount of one's 401K (or iRA) at the beginning of the period and dividing it by the difference between it and the current amount. It also factored in how to deal with contributions and withdrawals.

Can anyone point me to the formula?

Thanks!

[Waffle]

www.mymoneyblog.com/estimate-your-portfolios-rate-of-return-calculator.html

I'm not sure if I got the link in correctly, but maybe this will help. It's an online calculator, thought not a formula per se.

[Gardening Grandma]

Thanks! It gave me the same result for an anualized return (June, 2010 through June 2011), as what I had calculated manually, but it gave me a very different rate of return for YTD...

I'm bookmarking the calculator. Thanks again.