Openings for all films using a three day standard, movies opening on Thursday and Wednesday adjusted to a 3 day total. Thursday openers 75% of opening day added into the weekend, Wednesday openers 60% of first two days added into the weekend. My formula is basically, BS. However, it is rough tool to compare movies that opened on different days.

POTC-DMC-???
ROTS-$145.9m
Spiderman 2-$126.71m
Matrix Reloaded-$123.65m
Shrek 2-$120.6m
Spiderman-$114.8
Passion of the Christ-$108.65m
ROTK-$103.5m
XMen3-$102.75m
AOTC-$102.6m

I used to think some of these numbers might not be possible, but after seeing what ROTS and DMC were able to do, not so much anymore. ROTK probably would have had a hard time getting past $100m due to its running time, but I think the others are roughly accurate of what they would be able to accomplish in a three day weekend.

This looks somewhat reasonable. If that's the case, though, then Sith still would've held the record, as I don't think Pirates 2 will get to $145 million.

I have a different formula that uses the next week's grosses (the weekly drops to be exact) to determine how much of the first wed and thurs would have gone into the weekend. The numbers are actually quite similar to yours.

ROTS: 144m
The Matrix Reloaded: 123m
Spider-man 2: 121m (The Monday holiday messes with the formula a bit. Probably an underestimation here).
Shrek 2: 117m (A guess that's not actually based on the formula - it's useless in this case)
Spiderman: 114.8m
XMen3: 102.75m
HP4: 102.7m
The Passion: 101.7m (I used the formula in 3 different ways, and shockingly they were all within a few thousand of each other.)
AOTC: 100m

The formula usually underestimates due to the fact that film's level off. So, these numbers are slightly higher then the formula indicates by the amount of initial fanboy frontloading. So, I increased SW and Reloaded each be 2m-3m due to that factor, but kept The Passion the same (the numbers themselves showed no sign of initial frontloading for Passion - as I said, all the calculations were the same. The different calculations for fanboy films show a leveling off trend).

It's also useless for ROTK (due to the high weekdays in the second week).

I'm quite confident in the numbers. The math and logic behind it is solid, although it makes a few assumptions.

I don't believe this formula works. Take a 3 day opener like POTC 2. If it actually opened on a Wednesday or Thursday it would very likely have made even more than its 3 day TBD gross ( I estimate $138m). The % taken out of Wed and Thur in your calculation is an questionable assumption as it assumes that Wed and Thur eat away at 3 day grosses. In most cases, yes but not always.

For arguements sake let's pretend POTC2 opened on Wed and had a $50m OD, opening on a Friday helped in that more casual fans could go in the evening and night, than if it opened on a Wed. Then it had a $28m Thursday, $36.4m Friday, $40.4m Sat and $30.1m Sun for a $107m 3-day weekend and $185m 5-day total. Using my formula would give it a $153.8m opening 3-day weekend, so my formula is a rough approximation. POTC 2 might have done lower numbers than this if it opened on a Wednesday. I used SM2's numbers as a rough approximation, decreasing the numbers slightly since SM2 opened before the Fourth of July weekend and POTC2 opened the week after.

No that works, as it's already been brought up that there was a mad amount of sellouts last night, and at many places the screens couldn't fit the demand. If there was enough screens to house everybody, it probably would have gotten 150 mil+. That also probably means that while the formula says 145 mil+ for ROTS, because it only was released in 3600 theatres, it probably would've landed lower. I think Sith maybe could've hit 130 mil, but not much more.