Naps
How Long Should a Nap Be? 10, 20, 30 or 90 Minutes
For most adults, the best nap is short: about 10 to 20 minutes of sleep. In a lab study that pitted nap lengths against each other, a 10-minute nap gave the quickest lift, with benefits lasting up to about two and a half hours, while a 30-minute nap left people groggy before it helped [1]. If you are badly short on sleep and can spare the time, a nap of around 90 minutes is the other sensible option [2].
What each nap length does
Most nap advice traces back to a handful of careful experiments. The clearest is a 2006 study from Flinders University in Australia. Twenty-four healthy young adults, none of them regular nappers, slept only about five hours at home, then came into the lab at 3 p.m. and napped for exactly 5, 10, 20 or 30 minutes, or not at all. Researchers then tracked their alertness, mood and performance for the next three hours [1].
| Nap length (minutes asleep) | What happened afterward |
|---|---|
| 5 minutes | Few benefits compared with not napping |
| 10 minutes | Immediate gains in alertness, mood and performance, some lasting about 2.5 hours |
| 20 minutes | Gains that showed up about 35 minutes after waking and lasted up to about 2 hours |
| 30 minutes | A spell of reduced alertness and slower performance first, then gains lasting about 2.5 hours |
All results are from Brooks and Lack [1]. Note that the times are minutes of actual sleep, not minutes lying down. If it usually takes you five or ten minutes to drift off, set your alarm for that much longer.
The 10-minute nap won because it worked straight away. The 20-minute nap was nearly as good, just slower to pay off. Napping on a break and need to be sharp the moment you sit back down? That difference is the whole ballgame.
Why 30 to 60 minutes is the awkward zone
Sleep deepens in steps. You pass through light sleep first and usually reach deep, slow-wave sleep somewhere around half an hour in. Researchers think that delay is why naps of 30 minutes or less are less likely to leave you foggy [3].
So a 45- or 60-minute nap has bad timing built in. The alarm tends to catch you right in that deep stretch, before you have finished a full cycle, and the wake-up feels heavy. The Sleep Foundation adds that deep sleep can arrive even sooner when you are sleep deprived, which is exactly when you most want a nap [2]. If that heavy, sometimes queasy wake-up is what you are dealing with, our guide to why you can feel worse after a nap explains what causes it and how to clear it.
When a 90-minute nap makes sense
A full sleep cycle runs about 80 to 100 minutes [6]. Sleep for roughly that long and you have a fair chance of surfacing from lighter sleep at the end of the cycle rather than from the middle of deep sleep. The Sleep Foundation notes that a nap of around an hour and a half can help, especially for emergency workers and shift workers trying to stay ahead of fatigue [2].
The catch is time. Ninety minutes is a big block to carve out, and a long nap late in the day can get in the way of your night [2]. Cycle length also varies from person to person, so a 90-minute alarm is a best guess. We'd keep the long nap for a short night or a long shift rather than make it a daily habit.
Why the same nap works differently for different people
Length is only one dial. A review of the napping research looked at how time of day, age and experience with napping change what people get out of a nap [4]. Remember too that the Flinders volunteers were young and not used to napping, so your own sweet spot may sit a few minutes either side of theirs. And if you are sleep deprived, every length tends to feel heavier on waking, because deep sleep comes on sooner [2][3].
So use the numbers above as a starting point and experiment. Try 15 to 20 minutes in bed for a week. Waking up foggy? Trim it. Barely drifting off? Add five minutes.
Naps on a shift or after a short night
Some of the best real-world evidence comes from the cockpit. In a NASA study of long-haul flights, pilots were given a planned 40-minute rest window during the quiet cruise phase. They fell asleep in under six minutes on average and slept for about 26 minutes. Compared with crews who got no rest period, the nappers showed better alertness and reaction-time performance through descent and landing, and the nap did not disturb their sleep on the layover [5].
Those 26 minutes make a handy model for a nap at work. When in the day to take it is a separate question, answered in our page on the best time to take a nap. If you want an alarm time worked out for today, the nap calculator does the math.
How to get the length right
- Decide what you need: a quick lift (10 to 20 minutes) or recovery from a very short night (about 90 minutes).
- Add the time you usually take to fall asleep, and set the alarm for the total.
- Get up when it rings. Hitting snooze risks sliding into deeper sleep, and that is how a 20-minute nap turns into a 45-minute one [2].
- Leave yourself 15 to 30 minutes before anything demanding, in case some grogginess lingers [3].
If you need a nap most days just to get through the afternoon, or you nod off when you don't mean to, mention it to a doctor. Excessive daytime sleepiness can be a sign of a sleep disorder that is worth checking [2].
Frequently asked questions
How long should a power nap be?
About 10 to 20 minutes of actual sleep. In a controlled study of adults who had slept only about 5 hours, a 10-minute nap improved alertness and performance right away, while a 20-minute nap took around 35 minutes to start paying off [1]. The Sleep Foundation suggests about 20 minutes and no more than 30 [2].
Is a 30-minute nap good?
It can be, as long as you have time to recover afterward. In the Flinders University study, a 30-minute nap first left people less alert and slower, a sign of sleep inertia, before improvements kicked in and lasted for more than two hours [1]. If you need to be sharp the moment you wake, shorter is safer.
Is a 1-hour nap too long?
For most people on a normal schedule, yes. Around the 30-minute mark you are more likely to be in deep sleep, which is the stage that tends to cause the worst grogginess on waking [3]. An hour is long enough to get deep into that stage but usually too short to finish a full cycle, so it often gives you the downside without the cleaner wake-up.
Does a nap count toward my nightly sleep?
It adds to your total sleep for the day, but it does not replace a full night. A short nap gives you a burst of alertness, not the several complete cycles of deep and REM sleep a night provides [6]. If you find you need a nap every day just to function, that is a signal to look at your night-time sleep, and to talk to a doctor if the sleepiness persists [2].
Sources
- Brooks A, Lack L, Sleep. A Brief Afternoon Nap Following Nocturnal Sleep Restriction: Which Nap Duration is Most Recuperative? (2006)
- Sleep Foundation. Napping: Benefits and Tips
- Hilditch CJ, McHill AW, Nature and Science of Sleep. Sleep inertia: current insights (2019)
- Milner CE, Cote KA, Journal of Sleep Research. Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping (2009)
- NASA Ames Research Center (Rosekind MR et al.). Crew factors in flight operations 9: Effects of planned cockpit rest on crew performance and alertness in long-haul operations (1994)
- National Heart, Lung, and Blood Institute (NIH). How Sleep Works: Sleep Phases and Stages
This page is general information, not medical advice. Sleep needs vary; if you have persistent insomnia, loud snoring, pauses in breathing or daytime sleepiness that affects your safety, see a doctor.