financial for dummies: the 72 rule

the 72 rule gives fast, rough estimation on number of years required to double the money saved at a particular interest / dividend rate.

example: put rm5k in asb at annual dividend of 8%. the money will become 10k in...

72/8 = 9 years!

this is true if the dividend given is constant at 8%, the dividend received is reinvested back (as this formula caters for compounding interest as well) and no additional investment is performed (and none taken out, of course!).