As it's Tax Day, let's look at where our tax dollars come from and where they go.

The first chart shows the sources of federal revenue. The biggest source is individual income taxes, accounting for 46 percent of the total. Payroll taxes, split between the employer and employee, account for another 31.7 percent. Corporate taxes are a mere 13.5 percent and assorted customs duties, excise taxes and miscellaneous sources make up a few percent.

Source: National Priorities
Source: National Priorities

What we spend those trillions on can be seen in the chart below: 33.6 percent goes to Social Security and unemployment benefits. Medicare and health-related spending account for 26.6 percent. Next up are military spending and veterans' benefits, which capture a huge amount: 20.4 percent.

The last 20 percent or so goes to lots of smaller expenditures. Paying interest on our debt grabs 6.3 percent. The items rounding out federal spending are: food and agriculture (3.3 percent), transportation (2.6 percent), housing (2.6 percent), education (2.0 percent), energy (1.1 percent) and science (0.7 percent).

Source: National Priorities
Source: National Priorities

To contact the author of this article: Barry Ritholtz at britholtz3@bloomberg.net.

To contact the editor responsible for this article: Alex Bruns at abruns@bloomberg.net.