United Kingdom, May 9 -- Bill Gates has set himself a 20-year deadline to give away the majority of his fortune because he doesn't want to "die rich".

The Microsoft co-founder - who is believed to be worth an estimated $112 billion - has vowed to give away "virtually all" his cash through his Gates Foundation to help improve and save lives around the world over the next two decades with the charity now scheduled to close in 2045.

In a post on his blog, Gates revealed his plan has been inspired by the 1889 essay by Andrew Carnegie called 'The Gospel of Wealth' which suggests the wealthy have a responsibility to "return their resources to society".

The tech boss explained: "In the essay's most famous line, Carnegie argues that 'the man w...