Bedtime Calculator
Wake up feeling refreshed by timing your sleep around natural 90-minute sleep cycles
Enter your wake-up time and we’ll calculate the best bedtimes
Pre-filled with the current time — adjust if needed
Best bedtimes:
⏱ Includes 15 minutes to fall asleep
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How does this work?
Sleep is structured in roughly 90-minute cycles. Waking up between cycles — rather than mid-cycle — leaves you feeling alert and refreshed. This calculator adds a 15-minute sleep-onset window and finds times that align with completing a full number of cycles.
Sleep is structured in roughly 90-minute cycles. Waking up between cycles — rather than mid-cycle — leaves you feeling alert and refreshed. This calculator adds a 15-minute sleep-onset window and finds times that align with completing a full number of cycles.
Excellent (9h / 6 cycles)
Recommended (7.5h / 5 cycles)
Adequate (6h / 4 cycles)
Not recommended (4.5h / 3 cycles)
Based on 90-minute sleep cycles. Individual cycles vary. If you have insomnia, your cycles may differ — a sleep specialist can help.
⚠️ Important disclaimer: This tool is for self-monitoring and educational purposes only. It does not constitute medical advice, clinical diagnosis, or a substitute for professional treatment. Always consult a qualified healthcare provider before making any changes.