How would I self report my GPA on a 4.0, 4.5 and 5.0 scale for scholarships?

Weighted GPAs are not standardized, except when colleges or scholarships do their own recalculations (the best known of these is the UC/CSU method). Some high schools inflate weighted GPAs with exaggerated weightings, possibly hoping that some colleges and scholarships take them at face value (you may be competing against others whose high schools report a 5.something or 6.something weighted GPA).