According to the University of Michigan, kids spend roughly 1300 hours in school over the course of a 40-week school year. That is an average of 30.5 hours in school every week.
The number of hours spent in the classroom is only one part of the time commitment required from kids in school. They also have an average of four hours of homework per week plus an additional 15 minutes of commute time, on average, each way. That means kids devote about 1500 hours to school every year. Sports, social events and after-school clubs and activities increase this even more.