Below is a list of 28 of the wealthiest Americans ranked by how generous they are with philanthropic donations. We’ve calculated this list based on how much each person has given away over their lifetimes, as well as the percentage of their fortune they’ve donated. A value of 1 to 5 is assigned to each, with 5 being the most philanthropic. Bill Gates is the second wealthiest man in the U.S. (and the world) and received a ranking of 5. He has given away about 27% of his fortune. On the other hand, Jeff Bezos only gets a 2 despite being the richest man in the world. It should be noted that Bezos recently donated $2 billion to help the homeless. If that was distributed immediately, rather than over time, he would have gotten a 4. The “least” generous: The 1 Rupert Murdoch, News Corp., $13 billion net worth Room for Improvement: The 2s Jim Walton, WalMart, $45 billion net worth Jacqueline Mars, Mars, $28 billion net worth John Mars, Mars, $27 billion net worth Harold Hamm, Oil & Gas, $17 billion net worth Middle of the Pack: The 3s Elon Musk, Tesla, SpaceX, $19 billion net worth Len Blavatnick, Diversified, $16 billion net worth Abigail Johnson, Fidelity Investments, $12 billion net worth Alice Walton, WalMart, $44 billion net worth The Givers: The 4s Donald Bren, Irvine Group, $16.6 billion net worth Ray Dalio, Bridgewater Associates, $14 billion net worth Phil Knight, Nike, $29 billion net worth Sheldon Adelson, Sands Corp., $35 billion net worth Steve Ballmer, Microsoft, $40 billion net worth Sergey Brin, Google, $52 billion net worth Larry Page, Google, $53 billion net worth David Koch, Koch Industries, $45 billion net worth Charles Koch, Koch Industries, $45 billion net worth Larry Ellison, Oracle, $51 billion net worth The Cream of the Crop: The 5s Jim Simons, Renaissance Technologies, $15.5 billion net worth Paul Allen, Microsoft, $20 billion net worth Laurene Powell Jobs, Apple, $20 billion net worth Michael Dell, Dell Computers, $23 billion net worth Michael Bloomberg, Bloomberg LP, $56 billion net worth Mark Zuckerberg, Facebook, $57 billion net worth Warren Buffett, Berkshire Hathaway, $82 billion net worth Bill Gates, Microsoft, $96 billion net worth