Grade conversion for PhD application: Masters in France -> Phd in the US (Math) I am Masters student in France and I am considering pursuing PhD in the US.
 Grading in France seems to be less uniform then in other countries, which results (from my experience) in that getting 90% of max grade is hard. US universities have GPA requirements, some pretty harsh such as 3.5/4.0 GPA. 

A broad question is: what should I do, except from trying to get as high grades as possible,  to be admitted to a high rank institution in the US despite being on the verge of a GPA cut-off? A more specific one is: how are GPAs handled when the direct conversion of grades is difficult. 

I am looking for answers from people who have first-hand experience. There are a lot of answers in the internet, related to grade conversion for undergraduate school applications (that is, about conversion of high school grades), and there are conversion tables posted by some US universities. However, these answers does not answer my question well: I am interested in how thing are done in math/cs departments on the graduate level.
I do not tick any of the boxes in your requirements, but as no one seems to, I will try and help. I am a graduate student in the US in a different field than yours, but have had a similar question regarding conversion. 

Admission committees acknowledge that different countries have different grading schemes, some schools are stringent and some have grade inflation. First of all, do not try to 'game' your GPA to reflect what you think would be the comparison. That would come back and bite you in the... back. Often the schools will ask for the original grades in your native scheme, and sometimes to translate it to a GPA using their own calculator - which you should use. I wouldn't write an explanation about it for two main reasons - (a) it doesn't look good, and mainly (b) you are not a source of authority and they have no reason to trust you on this. Even if they did it does not mean that you can give a proper conversion.

OK. What should you do? The best possible thing will be to get your class rank from your department and mention that in your CV/Resume. Unless your grades are abnormally low, it is my understanding that the CV will be looked at - especially if you have a decent GRE, recommenders that are semi-known, or decent experience. Rank beats GPA. 
If that is not available, just assume that foreign students are given somewhat more leeway in the GPA department and your profile will gain a fleeting look if it is not all borderline.

Good luck!