The ideal class size for a martial arts class can vary depending on the style of martial art being taught, the age range of the students, and the level of experience of the students. Generally, a class size of around 10-15 students per instructor is considered ideal. This allows for individual attention to be given to each student while still maintaining a group dynamic.

As for the ratio of instructors to students, again this can vary depending on factors such as experience level and age range. As a general rule, one instructor per 10-15 students is a good starting point. However, if the class includes younger children or beginners who require more hands-on attention, it may be beneficial to have additional instructors or assistants present in order to ensure that all students are receiving adequate guidance and supervision.