Bedtime calculator
Choose when you need to wake up. The calculator works backward by six, five, and four approximate 90-minute sleep cycles.
What time should I go to bed?
Start with your alarm. Get three practical bedtime options.
Plan a bedtime
Includes 15 minutes to fall asleep.
Choose your alarmThree suggested bedtimes will appear here.
How this calculator works
The suggestions correspond to about nine, seven and a half, or six hours of sleep, plus fifteen minutes to fall asleep. Actual sleep-cycle length varies across people and across the night.
Use the estimate sensibly
Most adults generally need at least seven hours of sleep, but individual needs differ. A calculator cannot diagnose insomnia, sleep apnea, or persistent fatigue.
Common questions
Why 90-minute cycles?
Sleep stages recur in cycles often summarized as roughly ninety minutes. It is a useful estimate, not a biological appointment.
Why add 15 minutes?
It is a simple allowance for falling asleep. Adjust earlier if you usually need longer.
Is this medical advice?
No. Persistent sleep problems or daytime fatigue warrant advice from a qualified clinician.