The 15 richest self-made women on earth

The top tier of wealth in the world is a veritable boys' club, with only four women breaking the top 50. But that doesn't mean there aren't plenty of women who have earned huge fortunes for themselves as well.

With data from Wealth-X, a company that conducts research on the super wealthy, Business Insider has taken a look at the richest self-made women in the world. These women have built companies, pioneered new technologies, and made huge advances in their respective fields. They're worth a combined $53.1 billion - larger than the combined gross domestic product of Honduras, Iceland, and Cambodia.

The list includes household names like media mogul Oprah Winfrey as well as influential but lesser-known personalities such as Gap founder Doris Fisher.

Keep reading to see how these 15 women made their fortunes.