When should I call myself a software Engineer

After you create couple of software, preferably running on production serving real users 😉

The difference between the english and the german Wikipedia page is interesting:

• "Engineers, as practitioners of engineering, [...] invent, design, analyze, build, and test [...]" (english)
• "Engineer [...] is a status of experts in technology", "The grade Bachelor/Master of Engineering is commony acquired by studying 5 years", and "The job title Engineer is awarded only to graduates of the educational institutions mentioned." (german)

You see there's a big difference when it comes to practical and theoretical knowledge. In Germany the title "software engineer" is not very common due to the restrictions mentioned on Wikipedia, and also because the term "engineer" is historically linked with mechanics. I don't even know if I am allowed to call myself a "software engineer" officially. On the one hand I have studied IT for 5 years at 2 institutions that are both allowed to award the title "engineer", but on the other hand my bachelor was in "Wirtschaftsinformatik" (business IT), and my master was in IT management, so none of them is a pure engineering degree. However in both of them IT was a major, so actually I do call myself "software engineer" sometimes.