The US ranks ahead of all the other countries in the world in military spending. The following chart shows the top 20 countries based on their military expenditures in 2014:

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Source: CHARTS: U.S. Army size and defense expenditures relative to other nations, The Brookings Institution

The US. is not only the largest spender in the world but its total military spending is many times over the spending of other countries.

The chart below shows how the Federal Discretionary Spending amounts for 2015 is allocated:

Source: Federal Spending: Where Does the Money Go, National Priorities Project

Military accounts for more than half (or 54%) of the $1.11 Trillion spending.All other categories receive a portion of the remaining funds. For example, Transportation is one of the categories that receives a tiny portion of the overall discretionary spending of over $1.0 Trillion. It can be argued that this is one of the reasons why US infrastructure is such a dilapidated condition.

However despite such high spending the US Army branch of the military is still small relative to other countries as shown in the chart below:

Obviously a country having more active soldiers does not mean that country is superior militarily. Countries such as China and India have huge populations and labor charges are low. Hence they can afford to keep million man armies. North Korea is an exception.

Source: CHARTS: U.S. Army size and defense expenditures relative to other nations, The Brookings Institution