A good place to see the size of the US National Debt is the famous US Debt clock that is located on Sixth Avenue in Manhattan, New York City.
How large is the US National Debt ?
It is $17,682 Billion = $17 Trillion = £10.25 Trillion.
This is literally a sum of all the outstanding US Treasury Bonds outstanding, issued by the US Federal Government. This number is now over 100% of the US Annual GDP.
Another way of looking at it, is to divide it across the US population.
319 million is the US population.
$17,682 Billion = $17,682,000 million.
Thus:
$17,682,000 million / 319 million = $55,000 dollars per person in the US.
[=£33,000 per person in the US]
The scale of the US national debt is colossal.