"Dragons are long and narrow, so we can safely assume that Smaug can curl comfortably up on a treasure mound with same diameter as his body length – 19.2 feet.
How high is the mound? Well, at one point in The Hobbit, Bilbo climbs up and over the mound, and we know that Hobbits are approximately three feet tall. Assuming the mound is twice the height of Bilbo, we can say that the mound has a height of approximately 6 feet – like a six foot tall man climbing over a 12 foot mound of coins; substantial but not insurmountable.
To keep the math relatively simple and to avoid complications like integrating the partial volume of a sphere, we can approximate Smaug’s bed of gold and silver to be a cone, with a radius of 9.6 feet (1/2 the diameter) and a height of 7 feet (assuming the weight of the dragon will smush down the point of the cone by about a foot).
Now we can calculate the volume of Smaug’s treasure mound:
V= 1/3 π r2 h = 1/3 * π * 9.62 * 7 = 675.6 cubic feet"
Long story short, they value his treasure at about $8.6 billion. Not bad, eh?
You might also want to check out their list of the 15 richest fictional characters, featuring Bruce Wayne, Mr. Burns, Gordon Gekko and many more.
Can you guess who the richest fictional character is? Hint: He's not human.
(Forbes via io9)