The best bedtime is the one that lets you wake up at the end of a sleep cycle after getting enough total sleep. Most adults should aim for 5 or 6 cycles (7.5 or 9 hours), plus the 10 to 20 minutes it takes to fall asleep.
Find your wake-up time in the chart below and read across. Every bedtime already includes 15 minutes to fall asleep.
Free toolSleep CalculatorBest bedtime or wake-up time, based on 90-minute sleep cycles.Bedtime chart by wake-up time
| Wake-up time | 6 cycles (9 h) | 5 cycles (7.5 h) | 4 cycles (6 h) |
|---|---|---|---|
| 4:00 AM | 6:45 PM | 8:15 PM | 9:45 PM |
| 4:30 AM | 7:15 PM | 8:45 PM | 10:15 PM |
| 5:00 AM | 7:45 PM | 9:15 PM | 10:45 PM |
| 5:30 AM | 8:15 PM | 9:45 PM | 11:15 PM |
| 6:00 AM | 8:45 PM | 10:15 PM | 11:45 PM |
| 6:30 AM | 9:15 PM | 10:45 PM | 12:15 AM |
| 7:00 AM | 9:45 PM | 11:15 PM | 12:45 AM |
| 7:30 AM | 10:15 PM | 11:45 PM | 1:15 AM |
| 8:00 AM | 10:45 PM | 12:15 AM | 1:45 AM |
| 8:30 AM | 11:15 PM | 12:45 AM | 2:15 AM |
| 9:00 AM | 11:45 PM | 1:15 AM | 2:45 AM |
| 9:30 AM | 12:15 AM | 1:45 AM | 3:15 AM |
| 10:00 AM | 12:45 AM | 2:15 AM | 3:45 AM |
The 5-cycle column is the sweet spot for most adults. The 4-cycle column gets you through a single short night, but 6 hours isn't enough to live on. Here's why.
Need a time that isn't on the chart, or take longer to fall asleep? The sleep calculator works it out for any time in one tap.
How the chart works
Through the night your brain cycles through light sleep, deep sleep and REM (dreaming) sleep. One full loop takes about 90 minutes. Waking up near the end of a cycle, when sleep is already light, usually feels much easier than being pulled out of deep sleep.
So the chart counts back from your wake-up time in 90-minute steps, then subtracts 15 minutes for falling asleep. For a 6:30 AM alarm:
- 6:30 AM minus 5 cycles (7 h 30 min) = 11:00 PM asleep
- minus 15 minutes to drift off = 10:45 PM in bed
Which column should you pick?
- 6 cycles (9 hours): good if you're recovering from a rough week, training hard, or naturally need more sleep. Teens often need this much.
- 5 cycles (7.5 hours): the best everyday target for most adults. It fits inside the 7-to-9-hour range sleep experts recommend.
- 4 cycles (6 hours): a one-off for an early flight or a late night. Do it several nights in a row and you build sleep debt.
Why the times are a starting point, not a rule
Ninety minutes is an average. Real cycles run from about 70 to 120 minutes and change through the night: early cycles carry more deep sleep, later ones more REM. Your time to fall asleep varies too.
If you keep waking up groggy at one time, move your bedtime 15 minutes earlier or later for a few nights and see how you feel. Most people find their best time within a week.
Make your bedtime stick
- Keep your wake-up time the same every day, weekends included. It anchors your body clock more than anything else.
- Move bedtime in small steps. If you're used to going to bed at midnight, try 15 minutes earlier every few days instead of jumping straight to 10:15.
- Watch your afternoon caffeine. A 3 PM coffee can still be in your system at bedtime. Check your caffeine cutoff.
- Dim the lights an hour before bed. Bright light late in the evening pushes your body clock later.