Cumulative grade points average (CGPA) and cumulative rank in class is not calculated in the degree certificate. Neither are the grades transferred into grades in %. This is not applicable in Sweden and we do not have methods for calculating this, since Swedish degrees are not graduated with "first class with distinction, first class, second class upper/lower" and so on. The assessment is left to be done by the university that is asking for the CGPA. Due to this we do not recommend our students to use the GPA calculators on the Internet.
Another reason why we do not recommend the calculators on the Internet is because there are also so called "fake credential evaluators" on the Internet who invest a lot of time and money on what is called "search engine optimization", but they are not recognized and the calculators are not reliable because they tend to provide the best possible outcomes.