Taking a nap is like a quick reboot for your brain. But as much as napping can be enjoyable, it is also very much a science.

How long should one nap and when in order to get the most out of some shut-eye?

10 to 20 Minutes

According to The Wall Street Journal, this is what most people understand as a “power nap,” which is ideal for alertness and energy. This length of nap will make it easier to hit the ground running after waking up.

30 Minutes

Some experts believe that napping for 30 minutes may cause sleep inertia – a feeling like a hangover that takes as long as 30 minutes after waking up to get rid of.

60 Minutes

This nap is the best for improvement in remembering facts, faces and names. But an hour-long nap will also be proned to the hangover and grogginess feeling afterwards.

90 Minutes

This duration results in a full cycle of sleep. 90 minutes will lead to improved emotional and memory, specifically with tasks, and creativity. A nap this long usually avoids any feelings of grogginess or hangover like sleep inertia and you will be able to wake up easier.