Microsoft chairman Bill Gates remains America's richest person, according to Forbes magazine.

Gates, whose personal fortune is an estimated $53m, tops the annual list for the 13th consecutive year.

Berkshire Hathaway owner Warren Buffett is second on the list with a net worth of nearly $46bn.

Casino magnate Sheldon Adelson jumped 12 places to number three, closely followed by Oracle boss Larry Ellison in fourth and Microsoft co-founder Paul Allen in fifth.

Forbes said the wealthiest 400 people in the US all have a personal wealth of at least $1bn.

The combined net worth of the nation's richest 400 is $1.25 trillion, up from $1.13 trillion a year ago.

Four of the top 10 came from the Wal-Mart owning Walton family.

Google co-founders Sergey Brin and Larry Page were 12th and 13th respectively.

Brin, 33, is also the youngest billionaire on the prestigious list with a personal fortune of $14m.

Australian-born media tycoon Rupert Murdoch is ranked 32nd, while Apple chief executive Steve Jobs is placed 49th.

Also included in the list are Eric Schmidt, George Lucas, Ralph Lauren, Donald Trump, Peter Kellogg, William Wrigley and Oprah Winfrey.

However, Martha Stewart, founder of Martha Stewart Living Omnimedia, dropped out of the top 400 this year.

According to Forbes, California is home to 90 of the nation's 400 wealthiest tycoons, while 44 live in New York City.

Gates, 50, who set up Microsoft with Allen in 1975, is also known for his charity work.

The Gates Foundation, established in the name of Gates and his wife Melinda, has spent over $10bn since its inception in 1994, around half of which has been spent on global health issues.

The Top 5:

1.) Bill Gates - $53bn
2.) Warren Buffett - $46bn
3.) Sheldon Adelson - $20.5bn
4.) Larry Ellison - $19.6bn
5.) Paul Allen - $16bn