What is the synonym of standard?

normal, usual, typical, stock, common, ordinary, customary, conventional, habitual, accustomed, expected, wonted, everyday, regular, routine, day-to-day, daily, established, settled, set, fixed, traditional, quotidian, prevailing.

Which is something as accepted as a basis for comparison?

something considered by an authority or by general consent as a basis of comparison; an approved model. an object that is regarded as the usual or most common size or form of its kind: We stock the deluxe models as well as the standards.