Household net worth is the value of assets such as a house, car, stocks, retirement accounts minus debts, mortgages, credit card debt, etc. The median figure is what matters – it is the point at which half of people are richer than you and half are poorer than you. Mean is meaningless because people like Bill Gates skew the figures so far upward it isn’t useful for analytical purposes.
If you are 35 and under and your net worth – assets minus liabilities – is more than $11,800, you are above average. That seems like a really low bar, but it comes directly from the Census bureau.