cd ..BESTBEST
Health
Sleep Cycle Calculator
Calculate the best wake-up time or bedtime based on 90-minute sleep cycles. Includes sleep stage visualization, chronotype, sleep debt tracker, and nap calculator. Free.
best time to wake up calculatorsleep cycle alarm time calculatoroptimal sleep time calculator90 minute sleep cycle calculatorwhat time should i go to sleep
🌙 Calculate
⚙️ Personalize
Adult (26-64y): 7–9h recommended (NHS/CDC)
Average is 90 min. Can range 75–110 min per person.
How long it takes you to fall asleep. Average: 14 min.
🧬 Chronotype (unique to this tool)
💸 Sleep Debt Tracker
🌙 Go to bed at...
9:46 PM
6 cycles · 9h sleep
⭐ Recommended
11:16 PM
5 cycles · 7.5h sleep
⭐ Recommended
12:46 AM
4 cycles · 6h sleep
👍 Good
2:16 AM
3 cycles · 4.5h sleep
😐 Fair
3:46 AM
2 cycles · 3h sleep
😐 Fair
5:16 AM
1 cycles · 1.5h sleep
⚠️ Too little
⏱ Includes 14 min to fall asleep. Wake times align with end of a full cycle.
📈 Sleep Stage Visualization
awake
light
deep
rem
📊 Weekly Sleep Debt Tracker
6.5h
You're getting
8h
Recommended
-7.5h
Weekly debt
Recovery plan:
• Sleep 1.5h extra per night for 5 days to fully recover
• Prioritize this on weekends — Monday starts fresh
• Chronic sleep debt impairs cognition equivalent to 2 nights of no sleep
😴 Nap Calculator
⚡
Power Nap — 20 min
Alertness boost, no grogginess
wake 10:51 AM
💤
Full Nap — 90 min
One full cycle — full restoration
wake 12:01 PM
☕
Coffee Nap — 25 min
Drink coffee THEN nap — caffeine kicks in when you wake
wake 10:56 AM
⚠️ Avoid naps after 3pm — they reduce sleep pressure and delay bedtime.
💡 Evidence-Based Tips
→ Keep same wake time 7 days/week — bedtime can vary, wake time should not.
→ 18°C / 65°F is the optimal bedroom temperature for deep sleep.
→ No screens 30 min before bed — blue light suppresses melatonin for up to 3 hours.
→ Stop caffeine 8–10h before bed — caffeine half-life is 5–6h.
→ Alarm in another room — snoozing fragments sleep and increases grogginess.
→ 🐻 Bear (Middle): Follows sun — most common chronotype — adjust your schedule accordingly.
Frequently Asked Questions
What is a sleep cycle?+
A sleep cycle is approximately 90 minutes and includes light sleep, deep sleep, and REM sleep stages. Waking up at the end of a cycle (rather than mid-cycle) leaves you feeling more refreshed.
How many sleep cycles do I need?+
Most adults need 4–6 complete cycles (6–9 hours). 5 cycles (7.5 hours) is the most commonly recommended amount for adults aged 18–64.
What is a chronotype?+
Your chronotype is your natural preference for sleep timing. Lions wake early, Bears follow the sun, Wolves are night owls, and Dolphins are light, irregular sleepers. Each benefits from a shifted sleep schedule.