the age times income over 10 rule. Can you talk about this one? - This one was popularized by the wonderful book, "The Millionaire Next Door," which came out in 1995 or 1996. The idea here is to figure out what your net worth should be given your current age and income.

So the way that this rule works is you take your age and you multiply it by your pre-tax income, and then you divide that total by 10. This is a rough proxy for what your net worth should be. It was an example, let's say you were 50 years old and you make $100,000 per year.

Multiply those two numbers together, you get 5 million. You divide that by 10 and you get 500,000. Your net worth should be $500,000. And then from there, you can actually compare it to what your net worth is to figure out if you are doing better than the average person given your age and income, or worse than the average person given your age and income.