Bedtime calculator
What time should I go to sleep?
Choose when you need to wake up and calculate several possible bedtimes using approximate sleep cycles.
Choose your wake-up time
Calculation runs in your browser. No account is required.
How does a bedtime calculator work?
A bedtime calculator works backward from your desired wake-up time. This calculator subtracts your selected fall-asleep allowance and several approximate sleep cycles to produce possible bedtimes.
Calculation context
Sleep cycles vary
A 90-minute cycle is useful as a simple planning estimate, but it is not an exact rule for every person or every cycle.
Learn more from NHLBI / NIH and CDC sleep guidance .
Frequently asked questions
What time should I go to bed if I wake up at 7 AM?
The answer depends on how much sleep you need, how long you take to fall asleep and the cycle estimate being used. Enter 7:00 AM above to calculate several planning options.
Are 90-minute sleep cycles exact?
No. Ninety minutes is a convenient planning estimate. Real sleep cycles vary, so this calculator lets you choose an approximate cycle length from 80 to 100 minutes.
Should I choose the bedtime with the most sleep?
Adequate total sleep is important. The calculator provides timing options rather than guaranteeing that a particular bedtime will make you feel refreshed.