interest rate

The Rule of 72 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 a 9 percent interest, divide 72 by 9 and get 8 years.

When paying off debt, choose the credit card or loan with the highest interest rate first and pay that off, then move to the next highest interest rate, and so on.