Despite his resignation, which he told the New York Times he did at his investors' request, Kalanick will still sit on the company's board and maintain a majority of the company voting shares. Based on Bloomberg's estimate, Kalanick’s net worth is about $7.1 billion, largely thanks to his 12% stake in Uber—which is valued at about $70 billion.
According to Steve London, a partner at Pepper Hamilton who advises startups in the IPO process, Kalanick is unlikely to lose any of that. That's because while early stage investors commonly place a two to four year vesting period on company leaders and their shares as a condition for providing funding, Uber is already eight years old.
"It has been so long since the early stage investors put their money in that there is a slim, unlikely possibility that some of Kalanick's shares may be subject to restriction," London said.
So in theory, if Uber were to go public, Kalanick's stake in the company would likely have the same value regardless of whether he's CEO or not.
That said, Kalanick's resignation may cost him whatever compensation package he was offered as CEO, including bonuses and other benefits. But those figures are likely too small to bump his worth down from the billions-dollar range.