My D’s been taking 19 credits per semester due to orchestra and cello lessons, and Chinese is 5 credits (the other academic classes are 4 credits each.) I think it really depends on the student and how disciplined (determined) they are. Once she hit 16 credits there was no extra charge at her school except for cello lessons. She has to double up on writing courses for 2 semesters (already done one) in order to finish a double major within 4 years.