How's ''Superman'' doing so far?

Here’s a number you can take to the bank: Superman Returns will earn exactly $21,037,277 in 3,915 theaters in one day. I can say that for absolute sure, right down to the ha’penny.

Oh, okay, I admit it: I may do a heckuva job forecasting the box office, but I?m not that good. This week, my crystal ball has 20/20 hindsight, of course, since Warner Bros.’ big blockbuster premiered two days ago. According to Exhibitor Relations, that $21 mil single-day take ranks No. 8 all time for Wednesday openers, just trailing last summer’s War of the Worlds ($21.3 mil) but well behind Spider-Man 2 ($40.4 mil) and a handful of other movies with words like Lord and Rings and Star and Wars and Matrix and Passion of the Christ in their titles. So, you know, good start for Supes — not great, but no box office kryptonite, either. At this rate, the movie is unlikely to finish with an X-Men: The Last Stand-esque $102.8 mil over its first three-day weekend, but it does have super-strong reviews in its favor (how ’bout that 76 percent ”fresh” rating on RottenTomatoes.com, eh?), so it’ll land right around the same $65 mil that WOTW made exactly a year ago.

Fox’s The Devil Wears Prada is the weekend’s only other big bow, in 2,847 locations. This movie is also getting super-duper reviews (78 percent fresh on RottenTomatoes.com — take that, Clark!), and it sure seems like the perfect kind of counter-programming. It’s based on a popular book. It appeals to all the women who won’t want to see Supes in his spandex. And its star, the wonderful Anne Hathaway, boasts a devoted fan base of youngish ladies who helped both of the Princess Diaries movies open with nearly identical grosses just under $23 mil. That’s not far off from the $20 mil that this film will take in over the weekend — a figure that will place it in a dead heat with holdover Click come Sunday. See you then!