The US public debt is 72.5% of GDP. This is roughly equivalent to a person owing a debt of 72.5% of their annual income. High, but not impossible to pay off by any means.
Wikipedia [1] says $123.8 trillion, or ~$391k per capita (for the 2013 population of 316M). That's 7.23 years of GDP. That's actually much higher than I would have thought!
