Bill Gates set to become world's first trillionaire by 2042

Bill Gates is $915.6 billion away from becoming the world's first trillionaire, according to a new Oxfam report on wealth and inequality.

The report an economy for the 99% forecasts that Within the next 25 years, Gates' wealth could jump like never seen before.

The report said there were 793 billionaires worldwide in 2009. Added up, their net worths totaled $2.4 trillion. By 2016, the richest 793 people maintained net worths of $5 trillion — an annual growth of 11%.

"If these returns continue, it is quite possible that we could see the world's first trillionaire within 25 years," the report states.

In other words, Oxfam estimates that if trends hold, Gates — who's ahead of the pack on Forbes' list of the wealthiest individuals, at $84.4 billion in net worth — could stand alone on Forbes' future list of "The World's Trillionaires."

Not that Gates necessarily wants the distinction. Since leaving Microsoft in 2006, he has devoted his time and resources to eradicating infectious disease and improving education worldwide through the Bill and Melinda Gates Foundation.

But as Oxfam notes, wealth is incredibly hard to shrink once someone is so rich that spending is no longer an option.

"The super-rich can achieve returns that are not available to the ordinary saver, helping the gap to grow between the wealthy and everyone else," the report states. "The bigger the initial investment, the higher returns one can make as the initial costs of sophisticated advice and high-risk investments can be justified with the potential for super-lucrative returns."

As of 2013, Gates had donated at least $28 billion to the Gates Foundation. Unless the 61-year-old can figure out how to give even more away in the coming years, he could enter a never-before-seen class of wealth by the time he's 86.