How long should a power nap be?
Updated October 27, 2026 · Sources listed below
Short answer: 10 to 20 minutes of actual sleep. That's long enough to feel sharper and short enough to wake up before deep sleep makes you groggy. If you're badly short on sleep and have the time, a full 90-minute cycle is the other good option. Avoid 30 to 60 minutes.
Power nap lengths compared
| Nap length (asleep) | What to expect |
|---|---|
| 10 minutes | In a 2006 study in the journal Sleep, the 10-minute nap was the most effective length tested: alertness and performance improved right away and lasted up to about 2.5 hours, with almost no grogginess.[1] |
| 20 minutes | The classic power nap. Still mostly light sleep, so you usually wake up clear-headed.[4] |
| 26 minutes | The "NASA nap": pilots who napped about 26 minutes improved alertness by 54% and performance by 34%.[2] |
| 30 to 60 minutes | The riskiest range. You're more likely to wake out of deep sleep and feel groggy (sleep inertia) for a while before the benefit arrives.[1][3] |
| 90 minutes | A full sleep cycle, including REM. Better after a truly short night, if you have the time and it isn't late in the day.[5] |
The mistake almost everyone makes: timing from when you lie down
Every number above is minutes asleep. But a phone timer starts the moment you tap it. If it takes you 12 minutes to drift off, a "20-minute" nap gives you 8 minutes of sleep. If you fall asleep in 2 minutes, the same timer can run long enough to pull you into deeper sleep.
Two ways to fix it:
- Add your usual time to fall asleep. If you typically drift off in about 10 minutes and want 20 minutes of sleep, set the alarm for 30.
- Let a watch count real sleep. A smartwatch can tell when your heart rate settles and you stop moving, and start counting from there. That's what Power Napper does on Wear OS watches.
When to take a power nap
Early afternoon works best for most people, when the body's natural post-lunch dip in alertness hits. Mayo Clinic suggests napping before 3 p.m. so it doesn't get in the way of your sleep that night.[4] Shift workers can nap before a night shift instead.
Which length should you pick?
- You just need a quick reset at work or between classes: 10 to 20 minutes.
- You're about to drive or start a long shift: 15 to 20 minutes, ideally with a coffee right before (more on that in why naps make you groggy).
- You slept badly and have a free afternoon: 90 minutes, finished before mid-afternoon.
- You have 40 minutes until your next meeting: 20 minutes of sleep, plus time to fall asleep and wake up properly.
Frequently asked questions
What is the best power nap length?
10 to 20 minutes of actual sleep. Research found a 10-minute afternoon nap improved alertness for up to about 2.5 hours with little grogginess, and 20 minutes is the most widely recommended length.
Is a 30-minute nap too long?
Often, yes. Naps of 30 to 60 minutes are the most likely to end in deep sleep, which causes grogginess (sleep inertia). Keep it to 20 minutes asleep, or go for a full 90-minute cycle.
Why is the NASA nap 26 minutes?
In a NASA study of airline pilots, a planned nap that averaged about 26 minutes of sleep improved alertness by 54% and performance by 34%. 26 minutes is simply what the pilots slept in that study.
Should I count nap time from when I lie down?
No. The research lengths are minutes asleep. Add the time it usually takes you to fall asleep to your alarm, or use a watch app that starts counting when it detects sleep.
Sources
- Brooks & Lack, Sleep (2006): which nap duration is most recuperative?
- Rosekind et al., NASA Technical Memorandum (1995): strategic naps in operational settings
- Hilditch & McHill, Nature and Science of Sleep (2019): sleep inertia, current insights
- Mayo Clinic: Napping, do's and don'ts for healthy adults
- Sleep Foundation: power naps
This guide is general information, not medical advice. Power Napper is not a medical device.