All sorts of great questions come in on our Facebook page. One question we hear a lot is, How much of the federal budget actually goes to the military? In some charts, you see that military is more than half the budget. But in others, you see that it's much less than that. This week at National Priorities Project we're talking about all different kinds of budget pies, so this is our chance: Let's settle this once and for all.

Out of the total federal budget, the military accounts for around 18 percent.

But then there's the discretionary budget. You might be wondering, What's the discretionary budget? The discretionary budget is what lawmakers vote on each year during the appropriations process. It's different from "mandatory" spending, which lawmakers don't have to vote on each year. That's because mandatory spending includes programs like Social Security and Medicare, and the federal government automatically pays out benefits for those programs without lawmakers voting on whether or not to do so.

Mandatory spending accounts for around two-thirds of the total federal budget, while discretionary spending is around one-third. (Interest on the federal debt, a third category, makes up around 7 percent of total federal spending.)

The military accounts for 57 percent of discretionary spending.

And that's why you'll sometimes see that military is more than half of the budget, and sometimes you'll see that it's around a fifth of the budget. Got more questions? Check out Federal Budget 101 for more about mandatory and discretionary spending, plus a glossary, and a lot of other stuff too. You can also leave a comment below, or send me an e-mail at mattea [at] nationalpriorities.org.