The 400 richest Americans are now worth a combined $2 trillion, according to Forbes.

That sets a record, Forbes said, and marks a jump from last year's total of $1.7 trillion.

The average net worth of a Forbes 400 member is now $5 billion—also the highest ever. And the costs of being part of the 400 Club rose to $1.3 billion.

(Read more: Gates tops Forbes list again)

But it's the $2 trillion number that remains the most interesting. The 400 richest are now worth more than the GDPs of many nations—and they are worth more than most governments spend or tax.

Here is some perspective on what the 400 richest Americans are really worth.