Philanthropist and businessman Bill Gates has pledged to donate 99 per cent of his wealth to the Gates Foundation as he announced plans to wind down the charity organisation earlier than expected in 2045. 

Mr Gates made the announcement on Thursday — the day marking the 25th anniversary of the Gate Foundation; established alongside his ex-wife Melinda Gates in 2000.

“It’s kind of thrilling to have that much to be able to put into these causes,” Mr Gates said in an interview with The Associated Press.

The worth of Mr Gates’ pledge is estimated to be $107 billion as of today, which the 69-year-old said would be delivered over time and allow the foundation to spend an additional $200 billion over the next 20 years.

Mr Gates added, “I think 20 years is the right balance between giving as much as we can to make progress on these things and giving people a lot of notice that now this money will be gone.”

He also noted that the donation would allow the foundation to continue supporting various causes around the world, particularly education in the United States and global health in Africa, Asia and the Middle East. 

Mr Gates’ pledge was among the largest philanthropic gifts ever – outpacing the historic contributions of industrialists such as John D. Rockefeller and Andrew Carnegie when adjusted for inflation.

It trails the pledge made by Berkshire Hathaway investor Warren Buffett who also pledged to donate his fortune before death. His net worth is currently estimated by Forbes at $160 billion.