By not going off the cliff, the CBO estimates that deficits over the next decade would rise by a total of $7.7 trillion (that's "trillion" with a "T"). That would bring the total national debt somewhere to around $24 trillion by 2023 which is equal to 90% of GDP (that's pretty high). If we go off the cliff, don't expect a clean slate, though, as the nation would still have a significant budget deficit equal to 58% of GDP in 2023 due to all the mandatory spending associated with the impeding explosion in costs emanating from Social Security and Medicare.