Answer: "The baldachin is 96 feet high and weighs approximately 93 tons or 208,302 pounds" according to the book The Pilgrim's Guide To Rome's Principal Churches by Joseph N. Tylenda. One internet article put it at 98 feet, another 94 feet. The height of the canopy is somewhere around a 10 story building. That high, and it is inside, under the dome of St. Peter's!