What percentage of the U.S. federal budget is spent on entitlements?

It depends on how you look at it. A lot of spending gets moved around so it can be hard to track, for example some military spending isn't strictly allocated to the department of defense but it works its way there through other programs. Looking at the 2012. for entitlement spending there is mandatory spending, things like medicare and medicade, but there is also entitlement spending that goes on in funds that are allocated say to the department of health services. Without actually going through each departments books you can only give a rough estimitation. Here is a very rough guidline, it completely ignores how the departments are allocating spending.

Mandatory entitlements (Unemployment, Medicaid, Medicare, SS) : 2,009 million dollars about 56% of the 2010 Federal Budget

SS: 19%

Medicaid: 8%

Unemployment: 16%

Medicare: 12 %

Defense Spending (including overseas operations): 663 million dollars or 18%

Like I said earlier, these figures are probably lower than they should be because I am only using what the Feds have allocated specifically to those programs. Any monies that end up being used for those programs via other departments isn't shown.

Also, a nitpicking point. Anyone that says half our budget is used on defense is either lying or doesn't understand that they are simply looking at the discretionary budget. Of the federal budget of 3,551 million dollars, 1,378 of discretionary. Military spending is part of the discretionary budget. It is a trick politicians and overzealous activist often like to use to confuse and mislead the public. The truth of the matter is that both military and entitlement spending is way beyound what is sustainable.

*I've seen other figures that show this around 25% of total federal budget.