Want to know how long it will take to double your money at a given rate of return? Try the "Rule of 72."
Simply divide 72 by the amount of return to get the approximate number of years to reach your goal. For example at 6%, it will take 12 years (72 divided by 6 equals 12). But at 24%, it will only take three years (72 divided by 24 equals 3). This formula takes into account the compounding of your return each year.