What time should I go to bed to wake up at 4:45 AM?
Go to bed at
9:01 PM
5 cycles · 7h 30m of sleep
7:31 PM
6 cycles
10:31 PM
4 cycles
12:01 AM
3 cycles
Fine-tune
Includes 14 minutes to fall asleep.
Questions
What time should I go to sleep to wake up at 4:45 AM?
Go to bed at 9:01 PM for 5 full sleep cycles (7 hours 30 minutes), or at 7:31 PM for 6 cycles (9 hours). Both assume about 14 minutes to fall asleep.
What's the latest bedtime for a 4:45 AM alarm?
10:31 PM gives 4 cycles (6 hours). That's under the 7 hours adults need, so keep it occasional.
Why not exactly 8 hours before 4:45 AM?
8 hours would likely end mid-cycle. 9:01 PM lines your alarm up with the end of your 5th roughly 90-minute cycle, when sleep is lightest.