What Time Should I Go to Bed? A Simple Way to Decide

The honest answer to “what time should I go to bed?” is: it depends on when you have to get up. A good bedtime isn’t a magic number like 10 PM — it’s whatever time lets you wake at the end of a sleep cycle after enough cycles. Get that right and you’ll feel sharp even on slightly less sleep; get it wrong and nine hours can still leave you foggy.

Work backward from your wake-up time

Your body sleeps in cycles of roughly 90 minutes, moving from light sleep into deep sleep and then REM. Waking in the middle of deep sleep causes sleep inertia — the heavy, disoriented feeling that ruins a morning. Waking at a cycle boundary, when you’re already drifting toward light sleep, feels dramatically better.

So the method is simple:

1. Decide when you must wake up.
2. Count back in 90-minute blocks for 5 or 6 cycles (7.5 or 9 hours).
3. Add about 14 minutes for the time it takes to actually fall asleep.

You don’t have to do the arithmetic yourself — the sleep calculator does it instantly, and the bedtime chart lists the common wake-up times at a glance. But it helps to see the logic once.

Worked examples by wake-up time

Need to wake at 6:00 AM? Counting back 6 cycles (9 hours) plus onset puts your bedtime around 8:46 PM; 5 cycles (7.5 hours) lands at 10:16 PM.

Need to wake at 6:30 AM? Aim for 9:16 PM (6 cycles) or 10:46 PM (5 cycles).

Need to wake at 7:00 AM? That’s 9:46 PM (6 cycles) or 11:16 PM (5 cycles).

Need to wake at 8:00 AM? Try 10:46 PM (6 cycles) or 12:16 AM (5 cycles).

Notice the pattern: each option is exactly 90 minutes apart, because each represents one more complete cycle. Pick whichever fits your evening — both leave you waking at a boundary.

How many cycles should you aim for?

Most adults do best on 5–6 complete cycles, which is 7.5 to 9 hours. Four cycles (6 hours) can get you through an occasional short night without too much grogginess — because you’re still waking at a boundary — but make it a habit and you’ll start accumulating sleep debt.

Your ideal count also shifts with age. Children and teens need more; older adults often need a little less and have slightly shorter cycles. See the recommended hours by age for your band, then translate it into a bedtime with the calculator.

A quick bedtime guide by age

These are rough anchors assuming a 7:00 AM wake-up — adjust the bedtime if your morning is earlier or later:

• School-age children (need 9–11 hrs): roughly 7:30–8:30 PM.
• Teens (need 8–10 hrs): roughly 8:45–9:45 PM — though their body clocks naturally resist this, which is why consistency matters even more.
• Adults (need 7–9 hrs): roughly 9:45–11:15 PM.
• Older adults (need 7–8 hrs): roughly 10:00–11:00 PM, often with an earlier natural wake time.

Make the bedtime stick

Knowing your ideal bedtime is half the battle; actually hitting it is the other half. A few things that help:

• Anchor your wake-up time first and keep it consistent — even on weekends. A steady wake time stabilizes everything else and is the foundation of fixing a broken schedule.
• Set a “wind-down” alarm 30–60 minutes before bedtime, not just a morning alarm. The reminder to start heading to bed is often what’s missing.
• Dim the lights and screens in that wind-down window so melatonin can rise on schedule.
• Don’t chase a missed bedtime with extra caffeine the next day; it just pushes the problem later into the night.

What if I can’t fall asleep at my “ideal” bedtime?

If the calculator says 10:16 PM but you’re wide awake until midnight, don’t force it — lying in bed frustrated only trains your brain to associate bed with being awake. Instead, shift gradually: move your target bedtime 15–30 minutes earlier every couple of nights while holding your wake time fixed, and lean hard on morning light. Your body will catch up. Pin down your wake time, layer in the basics from the sleep hygiene checklist, and let your sleepiness migrate earlier naturally.

Frequently asked questions

Is 10 PM really the “ideal” bedtime? Not universally. The “10 PM is best” idea comes from the fact that it produces 7.5–9 hours for someone waking between 5:30 and 7:00 AM — a common schedule. If you wake at 9 AM, a 10 PM bedtime gives you 11 hours; if you wake at 5 AM, it gives you 7. Anchor to your wake time, not a headline number.

Should my bedtime be the same every night? Ideally yes, within about an hour. A consistent bedtime and wake time keep your circadian rhythm stable, which makes falling asleep easier and waking less groggy. Your wake time is the more important of the two to keep fixed.

What if my schedule changes day to day? Keep your wake time as steady as you can and adjust bedtime to still capture whole cycles. If you must get up earlier than usual, it’s often better to aim for one fewer complete cycle (waking at a boundary) than to squeeze in extra minutes that end mid-cycle.

Does going to bed earlier always mean better sleep? No. An earlier bedtime only helps if you’re actually sleepy then. Going to bed before your body is ready usually means lying awake, which is counterproductive. Move your bedtime earlier gradually and use morning light to pull your whole rhythm forward.

The bottom line

There’s no universal bedtime — only the one that fits your wake-up time and gives you 5–6 full cycles. Pick your wake-up time, let the calculator hand you the exact bedtimes, and protect the wind-down window before it. That’s the whole game.