The youngest member of the Kardashian-Jenner clan is also by far the richest.
Kylie Jenner graced the cover of Forbes magazine's August 2018 issue and fourth annual list of "America's Richest Self-Made Women." Forbes estimated that a then-20-year-old Jenner was "conservatively" worth $900 million.
In March 2019, Forbes confirmed that Jenner had become the youngest billionaire in the world — and the youngest "self-made" billionaire in history at just 21 years old.
The vast majority of that sum is thanks to her company Kylie Cosmetics, which Forbes currently estimates to be worth at least $900 million, boosted by her recent distribution deal with Ulta. As Forbes notes, the company has minuscule overhead with just seven full-time and five part-time employees, and Jenner owns all of it.
Jenner has also made millions from her family's reality show, her own short-lived spin-off show "Life of Kylie," her and Kendall's clothing line, endorsement deals with brands like Adidas and PacSun, and Instagram ads.
Source : https://www.businessinsider.com/ranked-kardashian-jenner-net-worth-2018-8