Bluebulb Projects' The Measure of Things presents:
2,500 is about one-and-one-fifth times the number of Steps in the Sears Tower.
In other words, it's 1.185 times the count of Steps in the Sears Tower, and the count of Steps in the Sears Tower is 0.8439 times that amount.
(a.k.a. Willis Tower) (Chicago, Illinois) (steps per stairwell)