The U.S. is the richest nation in the world (for now), and we claim more than twice as many billionaires as the runner-up. And yet we take second place when it comes to the number of female self-made billionaires -- which is surprising for a relatively progressive country that is defined by self-starters who made their own fortunes through hard work and innovation.

So who really wants to be a billionaire? Apparently, a lot of women from China.

According to the Hurun Research Institute, 49 of the world's 73 self-made female billionaires come from China. Their combined net worth is estimated at $95.4 billion. Meanwhile, there are only 15 in the U.S., with a combined net worth of $28.8 billion. Third on the list is the United Kingdom, with three self-made female billionaires boasting a collective $4.9 billion in wealth.

Meet the key players
Apparently hard work can pay off in China, too. At age 45, China's Zhou Qunfei is worth $8.3 billion, making her the world's richest self-made woman. Zhou earned her way to the top by founding Lens Technology, a leading manufacturer of glass covers for tablets and mobile phones, in 2003. The company is a major supplier for brands such as Apple and Samsung. Mainland-born Zhou grew up in poverty and began working in the glass industry in 1993. Today, her company has over 60,000 employees.

Second to Zhou is 74-year-old Chen Lihua. Known as the Beijing Real Estate Queen, Chen is the founder of Fuwah International Group, one of Beijing's largest commercial property developers. She boasts an impressive net worth of $7.7 billion and was only recently surpassed by Zhou.

Real estate is said to be the biggest source of wealth among China's richest females, representing about 25% of those on the current list. The next-largest wealth-creator is investments, accounting for 15% of China's richest women.

Although most of its wealthy females surely aren't billionaires, China is rapidly emerging as a leader in women's success stories. In recent years, the number of Chinese women in senior management positions has doubled, with 51% of those coveted high-profile jobs now held by females (versus only 20% in the U.S.). Additionally, about 21% of publicly traded China-based companies have women on their boards. Despite the all-too-common characterization of women as second-class citizens in China, they clearly seem to be rising above and proving their worth in the upper echelons of business.

Women still have some catching up to do
While the ranks of female billionaires are growing on an international level, men are still far ahead on the wealth accumulation front. Of the 1,826 known billionaires in the world, only 197 are women. While that number has increased since last year, when 172 female billionaires were reported, women still make up just 11% of the grand total. Furthermore, among China's richest, the 50 wealthiest men on record surpassed their female counterparts with an aggregate net worth about four times as great.

On top of that, only 29 of the world's female billionaires are self-made. The rest inherited their fortunes from the men in their lives, be they husbands or fathers. Christy Walton, the world's richest woman, for example, inherited a stake in Wal-Mart, which explains her estimated net worth of $41.7 billion.

That said, the U.S. has its fair share of astounding female success stories. Elizabeth Holmes made her money by founding Theranos, a blood testing company, at age 19. She is reportedly the world's youngest self-made female billionaire, with a net worth of $4.5 billion as of 2014. She is also the richest self-made female in the United States. 

Other notable examples include Diane Hendricks and Doris Fisher, who rank behind Holmes with respective fortunes of $3.7 billion and $3.1 billion. Hendricks made her money in the roofing business as the co-founder of ABC Supply. Fisher, meanwhile, cofounded the clothing retail giant Gap. Also on the list of self-made U.S. billionaires are Oprah Winfrey, with a net worth of $3 billion, and Hewlett-Packard CEO Meg Whitman, with a cool $2.1 billion.

So there you have it. Despite the wage gap between men and women, it is possible for women to amass huge fortunes if they have the vision and the willpower it takes. As today's leading self-made women have shown us, when it comes to achieving billionaire status, there's no single formula for success. But if anything, the achievements of Zhou, Chen, Holmes, and others like them should teach women everywhere to aim high and think big.

Maurie Backman has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.