I teach 3 classes each semester. One is 100% online. It takes me about 80 hours to set that up from start to finish, I do it in two weeks before the semester and after it is done I probably spend 1-2 hours each week doing things for students etc.
The other two classes take up 6 hours. So that, and the online one, are about 10 hours per week. They force me to have 6 hours of office hours. So I have to work 16 hours a week.
I have to publish and do research and that takes up most of my other time. I spend about 10-30 hours a week on that (do most of it during office hours), it all depends on how I feel. I guess I have a 16-26 hour work week on average, but that does not include faculty meetings, committee meetings etc.
The good thing is I make more than my buddies in law school and work fewer hours with no stress, but a hell of a lot less than my finance docs that went to Wall Street (one friends make over $1 mil last year - fvck, but he works 100 hours a week and is very stressed. His family is in China and they are poor (not anymore) so I am glad he made it, but my hours rock, and I get summers off, and they pay me to travel at least twice a year for conferences and I love traveling. I'm off from Dec 6th to Jan 8th and I can't wait.