Jun 2009
8
by micharch
Have you always wanted to be able to do compound interest problems in your head? Probably not, unless you're a sociopath, but it's a very useful skill to have because it gives you a lightning fast benchmark to determine how good (or not so good) a potential investment is likely to be.
The rule says that to find the number of years required to double your money at a given interest rate, you just divide the interest rate into 72. For example, if you want to know how long it will take to double your money at eight percent interest, divide 8 into 72 and get 9 years.
Rule of 72 calculator is included in the link below~
http://www.moneychimp.com/features/rule72.htm
Re: Rule of 72
That's news to me too. Thanks micharch! I detested working out compound interest in school.
Re: Rule of 72
Good find. Thanks for sharing. I hadn't seen this quick rule of thumb before.