Thank you :) In my university our GPA scale is inverted. The best you can achieve is 0.7 which corresponds to an A+ and the worst is 5.0 which is an F.

The HR (Human Resources) people at American companies are used to the American system of measuring Grades -- usually on the 4.0 scale (0.0 = F, 3.0 = B, 4.0 = A). Just convert your GPA to the 4.0 scale and write that on your resume. Or just write down "A+" average.

You want to make it as clear as possible that you are a strong applicant. Don't make the HR people think too hard about converting your GPA. They'll just get confused.

Wouldn't it be safer if he used some sort of percentile system? Something like 5%-10% for the GPA-equivalent exam in Egypt? (with the actual score afterwards in case they want to check).

This was the first thing I noticed.

I automatically associate the term 'GPA' with the American-style 4-point scale. I'm not aware that GPA is often used in other contexts. If this is understood on these terms, it will be an instant rejection.

There's also further confusion with 70% vs 86%.

Perhaps it would help to use the appropriate German term?

It's curious that the USA has effectively standardized on a 4 point GPA scale, yet Australia is still a complete catastrophe of marks. The universities in my city use a 7 point scale with 4 being a pass and 7 being 100%, meanwhile the one 100km south will use an American scale.

https://en.wikipedia.org/wiki/Academic_grading_in_Australia

I actually don't know whether it would be more appropriate when conveying my marks to those in other countries to convert, or to just explain the scale.

You might provide appropriate local conversions - to a 4.0 scale for US companies, for instance

To hazard a guess, 70% is the maximum grade (which I've been told isn't that good in US standards, so just saying "I've got 86%" - which is a very good grade, might get looked at the wrong way by a US company.

If I'm converting this properly that means in the States, he's actually a B/B+ student. 3.255813953 GPA. B+ being 3.3.