For UPENN how much would legacy boost my chances by?

Answered

It's hard to know exactly because Legacies come in all different flavors. If you are both a recruited athlete and a legacy you'd have a significant bump if you applied ED vs RD. But if you are a legacy but don't have amazing grades, course rigor, ECs, and test scores, then your legacy status isn't going to make up for the basic threshold criteria, (hopefully, that makes sense to you.)

I know UPENN is slowly changing their legacy priorities as evidenced in their website language:

Old Language: "We appreciate that attending Penn is a tradition for many families, so an applicant’s affiliation with Penn, either by being a child or grandchild of alumni, is given the most consideration through Early Decision."

New Language: "We appreciate that attending Penn is a tradition for many families. The Admissions Office identifies legacy applicants based on the information provided in a student’s application and defines “legacy” as being either a child or grandchild of alumni. Legacies who apply to Penn—like all applicants—receive thorough consideration in the application process."

So while the overall legacy population at UPenn is about twice the size of say Columbia, over time, it will be less significant.

The bottom line is that if you check off all the boxes that UPenn is looking for in terms of academics and institutional fit/priorities, your legacy status applying to ED will be a big boost in your admissions chances.