The Top 10 Richest Couples In The World, 2015

With a combined net worth of $85.7 billion, Microsoft Corp. co-founder Bill Gates and his wife Melinda Gates are the world’s richest couple, according to a study by private wealth consultancy Wealth-X, a firm that does research and valuations on ultra-high net worth individuals.

That’s more than the entire economy of Croatia or Bulgaria or Luxembourg.

Spanish retail tycoon behind the fashion chain Zara, Amancio Ortega Gaona and his wife, Flora Perez Flora Perez, occupied the number two spot in a list of world’s wealthiest couples, with a combined net worth of $70.7 billion.

Warren Buffett of Berkshire Hathaway and his wife Astrid Menks were ranked at the third position with a combined networth of $65 billion, followed by David and Julia Koch (4th, $47.5 billion), Charles and Elizabeth Koch (5th, $47.4 billion).

Here are the 10 richest couples in the world:

1. Bill Gates and Melinda Gates
Combined net worth: $85.7 billion
Country: U.S.
Source of wealth: founded the software giant Microsoft

2. Amancio Ortega Gaona and Flora Perez
Combined net worth: $70.7 billion
Source of wealth: Self-made; chairman of the Inditex fashion group, best known for the Zara clothing chain.

3. Warren Buffett and Astrid Menks
Combined net worth: $65 billion
Source of wealth: Self-made; Chairman and CEO of conglomerate Berkshire Hathaway

4. David and Julia Koch
Combined net worth: $47.5 billion
Source of wealth: Inheritance; Koch Industries, founded by his father Fred Koch, with his brother Charles.

5. Charles and Elizabeth Koch
Combined net worth: $47.4 billion
Source of wealth: Inheritance; Koch Industries, with his brother David.

6. Wang Jianlin and Lin Ning
Combined net worth: $40.7 billion
Source of wealth: Self-made; chairman of Dalian Wanda Group, a real-estate company and operator of movie theaters.

7. Jeff and Mackenzie Bezos
Combined net worth: $39.8 billion
Source of wealth: Self-made; Amazon.

8. Bernard Arnault and Hélène Mercier
Combined net worth: $38.7 billion
Source of wealth: Inheritance/Self-made; Arnault is the chairman and CEO of LVMH and he started out working for his father, Jean Leon Arnault, owner of a civil engineering firm Ferret-Savinel.

9. Mark Zuckerberg and Priscilla Chan
Combined net worth: $38.5 billion
Source of wealth: Self-made; Zuckerberg is the founder of social-networking site Faceboo

10. James and Lynne Walton
Combined net worth: $36.2 billion
Source of wealth: Inheritance; Walton is the youngest son of Sam Walton, the founder of big-box retailer Wal-Mart