Bill Gates makes major announcement that he's giving away nearly all of his fortune as he promises to spend $200bn

Bill Gates has revealed why he's ensuring his net worth drops by '99 percent over the next 20 years'.

The Microsoft founder has already given away $100 billion, however, he's now stated he's set to 'give virtually all' of his net worth away in the space of two decades.

In an announcement shared earlier today (May 8), Gates revealed, as done previously, he'll dole out much of his billions via the foundation he and his wife, Melinda, started 25 years ago - the Gates Foundation. And on December 31, 2045, he's revealed the foundation 'will close its doors permanently'.

But where is all the cash set to go and why is Gates getting rid of nearly all of it?

Why Gates is getting rid of 99 percent of his net worth

Well, after reading 'a lot of books' alongside a 1889 essay by Andrew Carnegie The Gospel of Wealth, Gates resolved to be 'determined' when the time comes for him to shuffle off this mortal coil, he will not be known as the man who 'died rich'.

"There are too many urgent problems to solve for me to hold onto resources that could be used to help people," he reflects in a post shared on his website, GatesNotes.

So, what better way to not be known for 'dying rich' than making sure his net worth drops '99 percent over the next 20 years' eh?

Gates added it's also a poignant year for him to make the announcement - 2025 marking 25 years since he and Melinda founded the foundation, alongside it being the year he turns 70, his dad 100 and Microsoft 50.

But how much is Gates really getting rid of and where is the money all going?

Gates had a lightbulb moment (Todd Owyoung/NBC via Getty Images)

Where 99 percent of Gates' $108 billion net worth is set to go

Ultimately, the money will go to the Gates Foundation 'to the cause of saving and improving lives around the world'. And Gates explained despite getting rid of 99 percent of his current $108 billion net worth, he expects the foundation to spend over $200 billion.

He said: "During the first 25 years of the Gates Foundation—powered in part by the generosity of Warren Buffett—we gave away more than $100 billion. Over the next two decades, we will double our giving.

"The exact amount will depend on the markets and inflation, but I expect the foundation will spend more than $200 billion between now and 2045. This figure includes the balance of the endowment and my future contributions."

The money is reported as going towards 'sav[ing] and improv[ing] as many lives as possible' from 'putting the world on a path to ending preventable deaths of moms and babies and lifting millions of people out of poverty' alongside helping fight 'deadly infectious diseases'.

"Progress depends on so many people around the globe: Brilliant scientists who discover new breakthroughs. Private companies that step up to develop life-saving tools and medicines," he added.

"Other philanthropists whose generosity fuels progress. Healthcare workers who make sure innovations get to the people who need them. Governments, nonprofits, and multilateral organizations that build new systems to bring solutions to scale. Each part plays an essential role in driving the world forward, and it is an honor to support their efforts."

The money will be given out via the Gates Foundation (Getty Images/Getty Images for Global Citizen)

Why it's a change of plans from the Gates' original proposal

Gates explained this newly announced plan marks 'a change from' him and Melinda's 'original' ideas for their foundation.

Upon launching it, the pair included 'a clause in the foundation's very first charter' which stated intentions for the organization to continue long after their deaths.

However, several years ago, Gates 'began to rethink' and realized the foundation's goals may actually be able to be achieved 'on a shorter timeline'.

He resolved: "The Gates Foundation’s mission remains rooted in the idea that where you are born should not determine your opportunities.

"I am excited to see how our next chapter continues to move the world closer to a future where everyone everywhere has the chance to live a healthy and productive life."