Calculate the ideal bedtime or wake-up time based on 90-minute sleep cycles for optimal rest.
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How this calculator works
Sleep occurs in 90-minute cycles. Waking at the end of a cycle (after stages 1-5) leads to feeling refreshed. This calculator subtracts the number of cycles × 90 minutes plus ~14 minutes to fall asleep from your desired wake time.
Common questions about this calculator
Persistent sleep problems may indicate a sleep disorder. Consult a sleep specialist if you consistently have difficulty sleeping.
