While it may not seem like it, some of America's wealthiest people are also the most generous. Every year, businessmen like Bill Gates and Michael Bloomberg make billions of dollars in charitable donations to support a variety of causes ranging from environmental issues to health care.
Business Insider and Wealth X calculated the generosity index of some of the world's biggest philanthropists based on their net worth and lifetime donations amount. Based on their results, here are the 10 of the most generous Americans:
10. Mark Zuckerberg
Generosity Index: 4%
The Facebook founder and self-made billionaire joined Giving Pledge, a commitment by the world's richest individuals to donate the majority of their wealth. Zuckerberg has made about $1.6 billion in lifetime donations, including $25 million towards the fight against Ebola, $75 million to San Francisco General Hospital, $120 million to Bay Area schools and $100 million worth of Facebook stocks to one of the New Jersey public school systems.
9. Michael Dell
Generosity Index: 6%
Michael Dell is the current CEO and chairman of Dell, one of the world's largest computer technology companies. Dell is the director of the Michael and Susan Dell Foundation which donates to causes related to education, community development and arts. In 2015, he assisted in building a new teaching hospital in Austin, Texas by donating $25 million. It is estimated that he has donated over $1.1 billion of his $18.9 billion net worth.
8. Michael Bloomberg
Company: Bloomberg Media
Generosity Index: 8%
The founder and CEO of Bloomberg media company lives by the 'you give what you can' philosophy. His first charitable donation was a $5 check to his college's alumni association, then the rest was history. He has since given over $3 billion in lifetime donations through the Bloomberg Foundation, which supports education, health care and environmental causes.
7. Paul Allen
Generosity Index: 12%
Just like his former partner Bill Gates, Microsoft co-founder Paul Allen is very generous. He's the chairman of the Paul G. Allen Family Foundation and has donated billions in his lifetime to healthcare and animal causes. His notable contributions include $7 million in grants to Alzheimer's research, $5 million to Seattle BioMed and $4 million to Global FinPrint, a conservation project for the preservation of sharks.
6. Pierre Omidyar
Generosity Index: 16%
Omidyar is the co-founder and chairman of eBay. The Paris-born Iranian-American businessman started the Omidyar Foundation which includes the Omidyar Network, HopeLab, Humanity United, and Ulupono Initiative. The foundation supports many causes including human rights, hunger relief and entrepreneurship. Omidyar is worth $6.2 billion and has donated over $1 billion to charity.
These wealthy individuals have donated billions and they still haven't cracked the top 5 of the generosity index.