Between your boss who swears she only needs 5 hours of sleep each night to your teenage cousin who spends half the day sleeping, people run the gamut when it comes to what they consider a “good night’s sleep.” But most of us aren’t getting enough, convincing ourselves we’re fine when, in fact, we can’t function without coffee and are stimulated from the bright lights emanating from our smart phones, tablets and TVs.

So how much sleep do you really need and how does it change as you age? Well, the National Sleep Foundation (NSF) put together an expert panel of 18 scientists and researchers and came up with a handy chart. It offers clearer guidelines on what constitutes a good night’s sleep, including increasing the sleep recommendations for young children and teenagers, who often don’t get enough shut-eye.

Along with the recommended amount of sleep, the full chart also provides a reasonable sleep range, based on age, which allows for individual differences. For example, although the NSF recommends that adults ages 26 to 64 sleep 7 to 9 hours each night, the chart shows that 6 hours or 10 hours of sleep per night is appropriate for some adults.

Here are the NSF’s sleep recommendations:

Newborns (0-3 months): 14-17 hours each day (previously it was 12-18)

Infants (4-11 months): 12-15 hours each day (previously it was 14-15)

Toddlers (1-2 years): 11-14 hours each day (previously it was 12-14)

Preschoolers (3-5): 10-13 hours per night (previously it was 11-13)

School age children (6-13): 9-11 hours (previously it was 10-11)

Teenagers (14-17): 8-10 hours (previously it was 8.5-9.5)

Younger adults (18-25): 7-9 hours (new age category)

Adults (26-64): Sleep range did not change and remains 7-9 hours

Older adults (65+):  7-8 hours (new age category)