Don't forget the work on the weekends of laundry, washing toys, etc. I normally add two hours per day. The one hour is for getting ready to open and parents arriving a bit early and the other half hour at the end of the day for cleaning up such as putting outside toys away. The other hour is for cleaning, meal prep, lesson planning. Also remember that your hours of work are from the time the first child arrives till the last child leaves so for many that will add an extra hour if you have some kids that arrive early and some that arrive later but then because of that go home earlier. I started out keeping track but quickly learned that it was pretty much the same every week so just started using the average.