Commentary Inf XXXIV 30-31

That is, 'I am, proportionally, closer in size to a giant than a giant is to Lucifer.' For the size of the giants, ca. 70 feet, see C.Inf.XXX.58-66. Let us, merely for purposes of calculation, agree that Dante was six feet tall. The equation is simple: 6/70 = 70/x; x = 817. Since a body is roughly 2.5 times one of its arm's length, Satan is approximately 2000 feet tall and thus looms, from the waist up, some thousand feet above the ice.