What time should you go to bed? How to calculate your ideal bedtime

"What time should I go to bed?" The answer isn't a gut feeling: it's a calculation. It depends on two simple things — the time you need to wake up, and how much sleep your body needs. Then you work backwards.

1. Start from your wake-up time

Your wake-up time is usually fixed (work, school, kids): that's your starting point. Calculate bedtime backwards from it, instead of going to bed "when tired" and enduring the alarm.

2. Add the right number of hours

Common recommendations:

• Children (6–12): 9 to 12 h
• Teens (13–17): 8 to 10 h
• Adults: 7 to 9 h

Example: an adult waking at 7:00 aiming for 8 hours should fall asleep around 11:00 pm.

3. Don't forget the time it takes to fall asleep

You don't fall asleep instantly — allow about 15 minutes. In the example, that means getting into bed around 10:45 pm, not 11:00.

4. Keep a regular rhythm, even on weekends

Very different weekday and weekend schedules create a tiring "social jet lag". Try not to exceed a 1-hour gap.

5. Protect the last hour before bed

Evening screens delay sleep onset. The last hour should be scroll-free, with a calm activity that signals to your brain it's time to slow down.