While he indulges in a few luxuries, they make up only a fraction of his fortune.
They've also pledged to give away most of their fortune through the Giving Pledge, which they launched in 2010.
Gates has invested in a variety of stocks and assets and launched a $1 billion investment fund, Breakthrough Energy, with 20 others.
Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation)
Despite his massive fortune, Gates previously told Ellen DeGeneres that when he became a billionaire at age 31 (history's youngest billionaire at the time), he didn't go on a spending spree.
It's been reported that Gates owns a Bombardier BD-700 Global Express, which costs $40 million and can seat up to 19 people.