Economic Fitness (EF) is both a measure of a country’s diversification and ability to produce complex goods on a globally competitive basis. The Universal Economic Fitness (UEF) extends this assessment to include services. Countries with the highest levels of EF or UEF have capabilities to produce a diverse portfolio of products and services, the ability to upgrade into ever-increasing complex industries, tend to have more predictable long-term growth, and attain a good competitive position relative to other countries. Countries with low EF or UEF levels tend to suffer from poverty, low capabilities, less predictable growth, low value-addition, and trouble upgrading and diversifying faster than other countries. The starting data is the UN-COMTRADE list of products and the IMF-BOP list of services exported by each country. This data defines a bipartite network of countries and industries. A suitably designed mathematical algorithm applied to this network leads to the Fitness of all countries and the Complexity of all sectors. The comparison of Fitness to the GDP reveals hidden information about the capabilities, development, and growth of countries.