I am in the State of Texas. Our school goes beyond the required clinical hours needed without simulation and as you can see our board states: http://www.bne.state.tx.us/practice/position.html#15.26. There is no ratio noted but it does give us the flexibility to assign reasonable hours for student prep time, scenario engaged timeframe, and post debriefing time. All together the students are given an hour to prep (pre/quizes & exercises), 1 hour to complete the scenario (includes-RN TO RN change over, scenario, documentation after the scenario), an hour for post (quiz/exercise), 45 minutes for debriefing. It is a process but never substitues for the clinical site. We have an ADN program, an LVN and LVN-RN transition program, and EMT/Paramedic program. What state are you in?