Some super-humans can survive on just a few hours of sleep, while others claim to be borderline narcoleptics. But the truth is your body needs a certain amount of sleep, and it is possible to get too much or too little.

It’s important to know the amount of sleep that’s right for you. Being under- or over-rested can result in irritability, inability to focus, a lack of productivity, and bunions! Okay, not really bunions, but it’s pretty serious regardless.

How Many Hours of Sleep Do You Need?

The National Sleep Foundation recommends hourly sleep ranges based on age. Generally, the older we get, the less sleep required. Newborns need twice the amount of sleep than older adults. That’s probably where the term “sleep like by baby” comes from — who wouldn’t love to sleep 15 hours a day! See where your quiz results rank next to NSF recommendations: As you age, you sleep less of your time in REM sleep.

But how many actual hours of shut-eye you need every day depends on many factors. Do you exercise? Where do you live? How old are you? It’s really not about total hours of sleep — it’s about the total hours of quality sleep you get. Less quality sleep means you’ll need more total hours to get the rest you need.