Sleep Calculator

Adults (18-64): 7-9 hours
Adults (65+): 7-8 hours
Teenagers (14-17): 8-10 hours

Find the best time to sleep or wake up based on 90-minute sleep cycles

Calculate

What time do you want to sleep?

What time do you need to wake up?

Include 15 min to fall asleep

Each sleep cycle lasts about 90 minutes. Waking up at the end of a cycle (rather than in the middle) helps you feel more refreshed.