What time should I wake up if I go to bed at 8:15 PM?

Wake up at 4:00 AM after 7.5 hours of sleep, or 5:30 AM after 9 hours.

These times let you finish whole 90-minute sleep cycles, including 15 minutes to fall asleep.

Personalise: age, time to fall asleep, cycle length

If you go to bed at 8:15 PM, wake up at one of these times:

1:00 AM
4.5 hours · 3 cycles
2:30 AM
6 hours · 4 cycles
4:00 AM
7.5 hours · 5 cycles
5:30 AM
9 hours · 6 cycles

Includes 15 minutes to fall asleep. Adults need 7 to 9 hours, so 7.5 hours (5 cycles) is marked as the best fit.

All wake-up times for a 8:15 PM bedtime

Wake up atSleepCycles
5:30 AM9 hours6Good for teens and people who need more sleep
4:00 AM7.5 hours5Recommended for most adults
2:30 AM6 hours4Short: below the 7-hour minimum
1:00 AM4.5 hours3Very short: only for an emergency

If you take longer to fall asleep

Time to fall asleepWake up after 5 cyclesWake up after 6 cycles
5 minutes3:50 AM5:20 AM
15 minutes4:00 AM5:30 AM
30 minutes4:15 AM5:45 AM

An early bedtime suits children, early risers and anyone with an early start. If you can’t fall asleep this early, it may be too early for your body clock: try moving bedtime later by 15 minutes at a time.

Frequently asked questions

What time should I wake up if I go to bed at 8:15 PM?
Wake up at 4:00 AM for 7.5 hours of sleep (5 sleep cycles), or at 5:30 AM for 9 hours (6 cycles). Both include 15 minutes to fall asleep.
How many hours of sleep will I get if I go to bed at 8:15 PM and wake up at 2:30 AM?
About 6 hours, or 4 full sleep cycles. That’s less than the 7 hours adults are advised to get.
Is 8:15 PM a good bedtime?
It is if it gives you at least 7 hours before you need to get up (8 to 10 hours for teenagers) and you can keep it most nights.

Other bedtimes

7:15 PM7:30 PM7:45 PM8:00 PM8:30 PM8:45 PM9:00 PM9:15 PM

For general information only, not medical advice. If you often feel tired despite enough sleep, snore loudly, or have trouble sleeping most nights, talk to a doctor.