Nap Calculator: when to set your alarm
Choose when you lie down and see wake-up times for a power nap, a short nap, or a full sleep cycle.
Which nap suits you?
| Nap | Length | Good for |
|---|---|---|
| Power nap | 10–20 min | Quick alertness boost |
| Short nap | 30–60 min | Only when needed; may cause grogginess |
| Full cycle | 90 min | Deeper recovery when you are short on sleep |
Tip: nap in a dim, cool room and finish by mid-afternoon to protect your night sleep.
Want everyday habits to try alongside this estimate? Read our practical guide to better sleep.
Frequently asked questions
What is the best nap length?
For most people a 10 to 20 minute nap gives a quick alertness boost without deep-sleep grogginess. A 90-minute nap covers a full sleep cycle.
Why not nap for 30 to 60 minutes?
Waking from deep sleep can cause sleep inertia, a groggy feeling that may last a while. It is not harmful, just less pleasant.
When should I stop napping for the day?
Late naps can make it harder to fall asleep at night. Many people do best finishing naps by mid-afternoon.
Do you add time to fall asleep?
Yes, we add 10 minutes for falling asleep. Adjust the start time if you fall asleep faster or slower.
More sleep tools
Sleep Calculator
Find the bedtime or wake-up time that lines up with your sleep cycles.
Caffeine Calculator
How much caffeine is still in you at bedtime, and your last-call time.
Sleep Debt Calculator
Add up a week of short nights and plan a realistic catch-up.
Bedtime Calculator
Age-based bedtime range for a given wake-up time.