How long should a nap last? What the evidence suggests

Go short: 10 to 20 minutes of sleep. The most consistent evidence on the subject points to brief naps as the ones that give the best immediate result in alertness and cognitive performance, while longer naps tend to leave you groggy on waking. There is no single number that suits everyone in every circumstance, though, and it is worth understanding why before you set the alarm.

Why the 10-minute nap looks like the most effective one

A laboratory study published in 2006 compared, in 24 healthy young adults, naps of exactly 5, 10, 20 and 30 minutes of sleep against no nap at all, after a night restricted to about five hours of sleep. The most-cited result is simple: the 10-minute nap produced immediate improvements in sleep latency, subjective sleepiness, fatigue, vigour and cognitive performance, with some benefits lasting up to 155 minutes afterwards. The 20-minute nap helped too, but the effects only appeared about 35 minutes after the nap and lasted up to 125 minutes. The 5-minute nap was barely distinguishable from not sleeping.

The 30-minute nap told a different story. Straight after waking, participants showed a spell of worse alertness and performance, what the authors described as sleep inertia, followed by improvements that lasted up to 155 minutes. In other words: the benefit came, but it came after a rough patch. The authors themselves concluded that, among the lengths tested, the 10-minute nap was the most effective overall.

None of which makes 10 minutes the universal answer. The study had just 24 participants, all healthy young adults, good sleepers, not in the habit of napping, tested after sleep restriction and napping at 3pm. That is a very specific picture. Your ideal length may be different, and the evidence does not define a single number for everyone.

So what about longer naps? A recent review offers another angle

A 2021 systematic review with meta-analysis, pooling 11 studies and 381 working-age adults, almost all in laboratory conditions, found improvements in cognitive performance after a daytime nap, mainly in alertness. The average nap length across the studies analysed was 55.4 minutes, considerably longer than the 10 to 20 minutes in the earlier study. The evidence is not monolithic: long naps also show up as associated with cognitive benefits, at least in a laboratory setting.

There are important nuances, though. The same meta-analysis reported that naps taken earlier, before 1pm, gave better cognitive performance, and that the benefits were independent of sex and age. Performance improved mainly up to 120 minutes after the nap, with contradictory results during the period of sleep inertia. Curiously, nap duration and the gap between the nap and the test did not influence cognitive performance. The authors call for more studies in real working conditions.

What should you take from that? Duration is not the only factor. The time of day counts. And the evidence is emerging, not settled: we still do not know the optimal length for each person, nor how these results translate outside the lab.

How to fit a nap into a real day

If you work for yourself or have some flexibility, try this. Book the nap for early afternoon, ideally before 1pm where you can. The 2021 review suggests earlier naps give a better cognitive result. Then pick a short length, 10 to 20 minutes of sleep, and set an alarm so you wake before you drop into deep sleep. If you surface with that heavy-headed feeling, give it a few minutes: in the 2006 study, the 30-minute nap produced exactly that inertia before the benefits turned up.

You do not need a bed. A reclining chair, a sofa, even the car seat with the car parked will do. What matters is that you can drop off without a big production and that you do not run far past 20 minutes. If you struggle to wake after 10, 15 or 20 may suit you better, but avoid going beyond 30, especially if you need to be functional straight afterwards.

On the days when it all goes wrong, when the nap ran to 40 minutes, when you woke up dazed, when you could not sleep at all, do not spiral. One failed nap does not wreck the day. If you come round with inertia, drink water, get daylight and give your body a few minutes. The evidence suggests the benefit may still arrive later, even after a poor start.

The mistakes that ruin a nap, and the ones that matter less

The most common error is letting the nap run too long, particularly if you have no room to wake slowly. The 2021 review points to better results with naps taken before 1pm, though that is an average and not a hard rule.

Some people also fret too much about the perfect environment. The 2006 study took place in a laboratory and still showed benefits from 10 minutes. A recent review concluded that the gap between the nap and the test did not influence cognitive performance, and its authors want more studies in real working conditions.

Less important still: body position, clothing, coffee before or after. We have no evidence that supports specific recommendations on any of this. If it works for you, keep doing it.

What if it is still not working after two or three weeks?

First, check whether you are actually giving the habit enough time. Then ask yourself whether a nap is the right answer to your problem at all.

If you have tried different lengths and different times and you still wake worse than when you lay down, it may be time to speak to a doctor or pharmacist. Napping is not compulsory, and some people simply do not get on with it. There is nothing wrong with you because of that.

Where melatonin fits, and where it does not

Nothing in the evidence available to us covers melatonin and napping, so we cannot say that it improves the quality or length of a nap. If you are thinking about a melatonin supplement to help you sleep at night, that is a separate question, and it is not one this page can answer on the evidence we have.

Should you decide to try one, a supplement such as Sleep Well Gummies from TuttiBear is an option. The daily dose of 2 gummies provides 1 mg of melatonin and is intended for adults, shortly before bedtime. It is not a treatment for napping and does not replace sleep habits. Always read the label and follow the warnings: do not exceed the recommended daily dose, it is not recommended for children, pregnant or breastfeeding women, and in case of illness or use of medication you should consult a healthcare professional before use. May cause drowsiness; avoid driving or operating machinery after taking. Contains polyols. Excessive consumption may produce laxative effects.

Whether to take it or not should be an informed decision, and if you are unsure, talk to your pharmacist or doctor.

When a nap stops being enough

Some signs should not be ignored. If you need a nap every day to function, if you wake tired even after a full night's sleep, if you nod off unintentionally during the day in risky situations such as driving, or if tiredness is interfering with work and relationships, seek medical help. A nap is a tool, not a diagnosis. And the evidence we have on ideal length is limited: we do not yet know the right value for each person, nor how laboratory results apply to real life.

What we do know is that, in one laboratory study of 24 healthy young adults, a short nap of 10 to 20 minutes in the early afternoon brought improvements, though those results may not apply to everyone. Try it, adjust it, and above all do not blame yourself if it does not work. Sleeping well is a process, not a recipe.