Hi, I graduated from a university in Nigeria. We don’t use the 4.0 scale, we use 5.0 grading system. Please, how do I convert it? I want to apply for a masters program.
You don’t. Unless the university specifically requests you to convert (highly unlikely), use the GPA on the 5.0 scale. If a university asks you to convert, it will tell you how to convert.
If you want an idea of your UW GPA in the states, I suggest googling a GPA calculator and putting it in that way.