I went to a P/F college and AMCAS calculated me a 0.0 GPA over zero credit hours (we didn't have credit hours either). 😛
In all seriousness, this is the wrong question to be asking. What is more important is what you have done to remediate your previous record. You could have a piss-poor overall UG GPA, but if the poor grades were 10+ years ago and you have been pulling a 3.8+ post bac GPA for the past couple of years, that will be taken into account, at least at my school. The adcom here wants to know that you are ready to do the work *now*. If you were a goof-off as a college kid, but you've turned your life around, that isn't viewed the same as if you didn't have this recent record of academic excellence. That being said, some schools will still screen you out if your overall GPA is below a certain number (3.0 for my state schools in FL). So if you still have a low overall GPA even with 2+ years of consistently excellent post bac work, you should be prepared to apply broadly and consider applying to DO schools as well. Best of luck to you. 🙂