Do physics graduate programs recalculate undergraduate GPA's for admissions? Do physics graduate programs recalculate undergraduate GPA's for admissions? 
This is quite common among medical schools but I would like to know if this is a common practice by natural science graduate programs. I have searched quite a few resources online and haven't found a conclusive answer. To clarify my question, recalculation means including EVERY course taken, even the first attempt of courses retaken for a higher grade (because of a grade of D- or lower when taken the first time).
I would guess that, independent of field, most places do some recalculation, even if informally. Some people/committees just put more emphasis on some things than others. 

There is also the situation that grading systems vary widely, especially if there are international students involved. 

However, if you have a specific worry that you took a course and did poorly, but then later re-took it and did fine, then that may show up, but it may not be the devastating issue that you fear. It might raise questions, but such things occur often enough that you aren't unique. You may need to explain the situation adequately and indicate that in spite of past problems you are a good candidate and likely to be successful. 

There can be a lot of reasons for a bad grade. But most people will look at the entire record, not just something that is anomalous. 

The only exception might be if the institution has so many applicants that it has to use crude measures, such as GPA cutoffs, to get the pool down to a manageable number.