HomeFree Calculators — Free Online Calculator ToolsSleep Calculator Sleep Calculator ???? Sleep Calculator Find your perfect bedtime based on sleep cycles I want to… Wake up at a specific time → find when to sleep Go to bed now → find when to wake up Wake Up Time Calculate ???? Sleep tip: Each sleep cycle lasts about 90 minutes. Waking up at the end of a cycle (instead of mid-cycle) helps you feel more refreshed. Allow ~15 minutes to fall asleep.
