I was asked a couple of weeks ago to come up with a guesstimate of what would be required to pay down the $13.6T federal debt. There are other people much more qualified to do this so I will borrow some of their ideas and numbers. My numbers will be very rough and not take into account inflation and population growth which have increased 24% and 10% respectively over the last 10 years. I will allow 30 years to pay down the debt just like a typical homeowner.

-The 2011 budget as submitted by President Obama is $3.8T
-Federal spending to date this calender year is $2.1T. Extrapolate and for 12 months it should be about $2.5T.
-That means we will have nearly a $1.3T annual deficit in 2011.

I came the following numbers from Barron's as reprinted on Seeking Alpha.
http://seekingalpha.com/article/2292...e?source=email

Using numbers from the above article:
Remember, the goal here is to figure out how to eliminate the federal debt but let's just start with balancing the 2011 budget before even addressing the debt. By raising the taxes on the rich to Clinton levels [[savings $400B), cutting government spending, all retirement benefits, military spending, and government health care expenditures all by 10% [[savings $330B), we would only have to come up with another $700B to balance the annual budget. That could be done by either slashing federal spending another 58% or by raising all sources of federal revenue across the board by another 28% or by some combination thereof. These figures do not include cutting federal interest because we haven't started reducing the federal debt yet. Let's do that next.

As previously noted, we have about a $13.6T federal debt. At 4.5% interest, we could collectively pay down our federal debt, including interest in 30 years by paying off $827B a year [[from an amortization table). So in addition to federal budget cuts and tax increases in the preceding paragraph, taxes would have to be raised an additional 33 %.

The answer to the question then is that to balance the annual budget and pay off the federal debt including interest at 4.5% interest over 30 years, we will have to increase federal taxes of every sort [[income, payroll, corporate, excise taxes and duties) by 61% and make the 10% cuts as mentioned two paragraphs above. This is, of course, without cost overruns and any starting new federal programs.

-http://en.wikipedia.org/wiki/United_States_federal_budget
-http://www.usdebtclock.org/index.html#