With defense spending totaling $610 billion in 2017, the U.S. spends more than any other country on military in the world. China ranks second. But as a percent of gross domestic product, the U.S. spends about 3.3%, far less than some countries.
The CIA keeps track of this stuff, because, well, that's what the CIA does. Based on the data from the CIA's World Factbook, these are the countries that have the highest military expenditures as a percent of gross domestic product, calculated on an exchange rate basis. The data is from 2016, unless otherwise noted.
See where the U.S. falls on this list of countries spending the most on their military.