THE RULE OF 72

THE RULE OF 72 is an easy way to work out
how long it will take you to double your money
if you deposit it into a bank
and allow compound interest to work over a period of time,
at a particular interest rate.

The Rule of 72 says:
Divide 72 by the interest rate you expect to earn.
And that will tell you the number of years it'll take you to double your money.

For example, say you estimate the average interest rate over the next years to be 3%.
72 divided by 3 is 24.
That means that it will take you 24 years to double your money.