Bluebulb Projects' The Measure of Things presents:
8,400 is about four times the number of Steps in the Sears Tower.
In other words, it's 3.983 times the count of Steps in the Sears Tower, and the count of Steps in the Sears Tower is 0.2511 times that amount.
(a.k.a. Willis Tower) (Chicago, Illinois) (steps per stairwell)