Bill Gates tops Forbes list of US rich with net worth of $72 bn

Microsoft founder Bill Gates is on top of the Forbes list of America's richest for another year with a net worth of $72 billion in 2013, followed by Warren Buffett, with a fortune of $58.5 billion.

Buffet, 83, is the top gainer with a net addition of $12.5 billion to his fortune, bringing his net worth to $58.5 billion in 2013, despite giving away about $1 billion last year.

Oracle CEO Larry Ellison is in the third place with a net worth of $41 billion.

Right-wing industrialists Charles and David Koch are in the fourth and fifth spots, with three Waltons, who own retail chain Wal-Mart, taking the seventh, eighth and ninth spots.

New York mayor Michael Bloomberg is in tenth spot with a net worth of $31 billion.

The Forbes report on richest 400 Americans show that their total wealth increased to $2.02 trillion in 2013 from $1.7 trillion last year with younger Americans accumulating wealth at a faster pace.

The annual Forbes 400 wealthiest Americans list showed that total wealth climbed 19 per cent in the last year to $2.02 trillion, up from $1.7 trillion, with an average net worth per individual of $5 billion, up from $ 4.2 billion in 2012.

It now takes $1.3 billion in assets just to get on the list.

Facebook CEO Mark Zuckerberg, with a fortune of $9.6 billion, is back in the top 20 list buoyed by last year's record IPO proceedings.

Carl Icahn who lost his battle to stop Dell from going private, however, is back among the top 20 in the Forbes list for the first time since 2008.

The younger billionaires include the famous names in the information technology industry like Facebook's Mark Zuckerberg (ranked 20th), Computer maker Michael Dell (25), Yahoo's Jerry Yang (327), Tesla Motor's Elon Musk (61) and Google's Larry Page and Sergey Brin (13 and 14).

A separate survey by Forbes also showed that the youngest of the new generation millionaires – the Gen X and Gen Yers - are earning more money and amassing more with average salaries of $677,000 for those 48 and younger compared to $198,000 for those older, and total average assets of $5.7 versus $5.2 million.