LOS ANGELES (BLOOMBERG) - Kylie Jenner, the founder of Kylie Cosmetics, has become the world's youngest self-made billionaire after her company signed an exclusive partnership with Ulta Beauty.

Jenner, 21, is worth US$1.02 billion (S$1.38 billion), according to the Bloomberg Billionaires Index, which assumes that she owns 90 per cent of her company and ascribes the rest to her mother Kris, who takes a management fee in exchange for handling public relations and finance.

Forbes, relying on a different methodology, reported earlier on Tuesday (March 5) that Jenner had achieved the milestone.

Jenner, the half sister of Kim Kardashian, founded Kylie Cosmetics in 2015. The company posted US$360 million of revenue last year, a 9 per cent increase from 2017, according to Forbes.

Bloomberg values Jenner's firm by comparing it with four publicly traded peers: L'Oreal, Inter Parfums, Estee Lauder and Elf Beauty.

Kylie Cosmetics outsources its manufacturing and packaging to Seed Beauty and sales and fulfilment to Shopify. The details of those arrangements are not public and could alter the valuation.

Bloomberg classifies people as self-made if they do not inherit their wealth through marriage, death or bequests.

Jenner, the youngest member of the Kardashian-Jenner clan, has amassed 128 million Instagram followers and leveraged that popularity to promote her products.

There were 22 Singaporeans who made the list, with real estate barons Robert and Philip Ng - who control Far East Organization, Singapore's largest private landlord and property developer - coming up tops among their countrymen at a joint 112th, with US$12 billion.

Second among the Singaporeans in the ranking was paint tycoon Goh Cheng Liang, whose wealth comes largely from a 39 per cent stake in Japan's Nippon Paint Holdings. He was ranked at No. 203, with his fortune worth US$7.2 billion.

Coming in third was Mr Zhang Yong, the founder of popular Sichuan-style hotpot chain Haidilao, at 224th place, with US$6.8 billion.