He's already worth $90 billion. In other words, if he were a country, he'd be the 63rd largest economy in the world.
The famously philanthropic Microsoft co-founder has donated more than $30 billion dollars to his charity.
But Oxfam has found that since 2009, the world's richest have benefited from an 11% annual rate of return, which puts him on track to be a trillionaire by the age of 86.
But some say, not so fast, noting Gates' wealth has only grown 4%, not 11% since he left Microsoft in 2006.
Gates and fellow billionaire friend Warren Buffet have both pledged to donate at least half of their fortunes.
At 86-years-old, Buffet may not reach trillionaire status in his lifetime, but that hasn't tapered his appetite for buying stocks.
After his favored candidate Hillary Clinton's loss, Berkshire Hathaway bought $12 billion dollars worth of stock.
Highest-earning dead celebrities
Highest-earning dead celebrities
MJ may have died over six years ago but his legacy still lives on. The King of Pop made $115m this year, but how? Cirque du Soleil in Vegas showcasing Michael Jackson One is one of the source's of Michael Jackson's cash flow but the Mijac Music catalogue and music sales also contribute.
Elvis pulls in most of his money from ticket sales at his Graceland home. Now it may seem surprising that this rock and roll legend could generate that much income from tours of his home, but it makes more sense when you realise a regular adult ticket will set you back $77!
The Marley Beverage Company and House of Marley are just two of the companies bringing in the big bucks for reggae legend Bob Marley. Music sales are also obviously a huge contributor with more than 75 million albums sold so far.
Celebrity fragrances might not really be that sought after any more but White Diamonds, one of Elizabeth Taylor's perfumes, was first released 24 years ago and continues to be sold to this day proving that maybe there really are some things that never go out of fashion.
Marilyn Monroe is undoubtedly still an international fashion and film icon. In 2011, Authentic Brand Group bought the rights to her brand and it's thanks to them that she's still pulling in top dollar as well as a clothing line at American store, Macy's, and a range of lingerie.
John Lennon was part of one of the biggest musical acts of all time, The Beatles, although unfortunately his stardom was cut short when he was shot dead in 1980. The songwriter still gets his share of the album sales though and is reported to take $12 million each year.
Einstein is one of the most famous scientists in history having come up with the general theory of relativity. Branded mechandise and memorabilia is the main source of the theoretical physicists revenue now though.
Paul Walker was just 40-years-old when he died in 2013 in a car crash, but his legacy still lives on thanks to the film franchise, The Fast and the Furious. The most recent film took $1.5 billion and although Walker died during filming, he still appears in the flick.
Bettie Page was one of America's iconic pin-up girls, even gaining the nickname 'Queen of Pinups' thanks to her trademark look. The model was also one of the earliest Playmates of the Month to feature in Playboy magazine. Page now makes most of her money at the hands of fashion, clothing and lingerie lines.
Theodor Geisel was responsible for some of the quirkiest and best-loved cartoon characters and children's book heroes. The artist and author published his works under the title of Dr.Seuss with some of his most famous creations including The Lorax, The Grinch and The Cat in the Hat still netting him money to this day.
Not to be confused with the award-winning film director of the same name, Steve McQueen was, at one point, one of the highest paid film stars in the world. Some of McQueen's most famous films include The Thomas Crown Affair, The Magnificent Seven and The Great Escape. His image is still used in adverts and commercials, bringing in $9 million worth of revenue.
James Dean was a certified heartthrob and cultural icon of the 1950s who sadly died in a car accident at the age of just 24. His iconic image has been used throughout the last 60 years in a variety of ways all of which have been bringing in the cash. Most recently Dean's image was featured on a designer Dolce & Gabbana tshirt.