Like for example, a college says their average freshmen admit high school GPA is a 3.8. Is this UW or W?
Depends upon the school. Most will post if they are weighted or unweighted (4.0 or 5.0 scale).
According to the CDS they are SUPPOSED to use UW GPA on a 4.0 scale. I know that many do not (looking at you UNC). I think they should be required to fix that but I’m not in charge.
Depends on the school. Some colleges even recalculate HS GPAs entirely according to their own criteria (ex. academic subjects only).
My local HS does not weight GPAs but that seems to be taken into account in the admissions process.
It depends on the school. However, if a school uses wGPA, they use their only way of calculation. In other words, the wGPA on your transcript mostly means nothing to the school. Even for uwGPA, colleges often recalculate it too as some classes may be excluded. Some schools would skip freshmen grades while others skip subgrades.
So if says it is a 4.0 scale that means UW? Weird, because my high school uses a 4.0 weighted scale and a 4.0 unweighted scale. Would colleges recalculate my weighted GPA then if they use a 5.0 scale?
It depends on the school.
Some colleges like the UC’s will recalculate it, while some other schools just look at the letters on your transcript.