When Should I Wake Up?
Enter your bedtime to find optimal wake-up times
Results update automatically as you adjust the time
How to Use Sleep Calculator
- 1 Enter the time you plan to go to sleep
- 2 See optimal wake-up times for 3-6 cycles
- 3 Set your alarm for the recommended time
- 4 Wake up at the end of a cycle feeling refreshed
What You Get
Calculates when you should wake up to complete full sleep cycles. Waking at the right time prevents morning grogginess.
Input: Sleep at 23:00
Output: 5:00 (4 cycles), 6:30 (5 cycles), 8:00 (6 cycles)
Input: Sleep at 00:30
Output: 6:30 (4 cycles), 8:00 (5 cycles), 9:30 (6 cycles)
What is the best time to wake up if I go to bed at 11pm?
For an 11:00 PM bedtime, optimal wake times are 5:00 AM (4 cycles), 6:30 AM (5 cycles), or 8:00 AM (6 cycles). Waking at cycle end prevents grogginess.
Should I sleep 4, 5, or 6 complete cycles?
5 cycles (7.5 hours) is ideal for most adults. Use 6 cycles if sleep-deprived. 4 cycles is minimum for occasional short nights.
Why do I feel worse with more sleep?
Sleeping too long may mean waking during deep sleep. 9 hours may not align with your cycles as well as 7.5 hours does.
Does the time I go to bed matter for sleep quality?
Yes. Sleep quality is highest between 10 PM and 2 AM due to natural melatonin peaks. Try to get some sleep during this window.
What time should I wake up to feel energized?
Wake at the end of a complete 90-minute cycle. This is when you are in light sleep and will feel most alert and refreshed.
How do I calculate when I should wake up?
Add 14 minutes for falling asleep, then add 90 minutes for each cycle (4-6 cycles). Example: 11 PM + 14min + 5×90min = 6:30 AM.
All calculations happen locally in your browser. No data is sent to any server.