That means granddaughter Paris Hilton, who once stood to inherit $100 million or more by some accounts, could end up with a measly $5 million or so.
"The whole family will be devastated, particularly [Paris' mom] Kathy," a pal of the clan told the Daily News last night.
"Some of them could be likely to contest the will – it'll be in the courts longer than Anna Nicole Smith versus J. Howard Marshall."
Barron Hilton is worth an estimated $2.3 billion, including the $1.2 billion he made from the sale of the Hilton Hotels and Harrah's casino chains.
All but 3% of the money will go into a charitable trust to benefit the Conrad N. Hilton Foundation, which was started by his father, the foundation announced yesterday.
The foundation funds clean water in Africa, education for blind children and housing for the mentally ill.