United States's defence budget is the highest in the world. United States's defence expenditure is estimated to be US$731,751M (3.40% of its GDP). Its percentage of GDP allocated to defence spending is the highest in North America.
With a 2,233,050-strong military, United States has a per-capita ratio of 6.8 military personnel per 1000 in population. Its total military consists of 1,388,100 active personnel (third-largest in the world) and 844,950 reserve personnel.
United States's battle tank force is the largest in North America. On land, United States has a mobile force of 8,850 tanks. For aerial defence, United States has an air force of 14,061 military aircrafts and 3,720 attack helicopters.United States's naval fleet is the second-largest in the world. United States has a naval fleet of 254 vessels, including 11 aircraft carriers and 70 nuclear submarines. Rounding up the fleet of warships are 21 frigates, 69 destroyers and 27 corvettes.