The person who can best judge how much sleep you need is yourself. If you're feeling tired, you probably need more sleep. But the science also provides some clues.
The magic number is 7. People who sleep seven hours a night tend to be healthier and live longer. Sleeping less than seven hours has been linked to a range of health problems, such as obesity, heart problems, depression and a weakened immune system. But actual sleep needs vary from person to person. Age, heredity, lifestyle and environment are all factors that influence sleep needs. The National Sleep Foundation (NSF, USA) recently published their recommendations for sleep duration based on a person's age.
age |
Recommended sleep duration in hours |
Adequate amount of sleep in hours |
Not recommended hours of sleep |
|
newborn 0 - 3 months |
14 - 17 hrs |
11 - 13 hrs 18 - 19 hrs |
Less than 11 hrs More than 19 hours |
|
baby 4 - 11 months |
12 - 15 hrs |
10 - 11 hrs 16 - 18 hrs |
Less than 10 hrs More than 18 hours |
|
toddlers 1 - 2 years |
11 - 14 hrs |
9 - 10 hrs 15 - 16 hrs |
Less than 9 hours More than 16 hours |
|
preschoolers 3 - 5 years |
10 - 13 hrs |
8 - 9 hrs 14 hours |
Less than 8 hrs More than 14 hours |
|
school children 6 - 13 years |
9 - 11 hrs |
7 - 8 hrs 12 hours |
Less than 7 hours More than 12 hours |
|
teenager 14 - 17 years |
8 - 10 hrs |
7 hours 11 hrs |
Less than 7 hours More than 11 hours |
| Young adults 18 - 25 years |
7 - 9 hrs |
6 hours 10 - 11 hrs |
Less than 6 hrs More than 11 hours |
|
adult 26 - 64 years |
7 - 9 hrs |
6 hours 10 hrs |
Less than 6 hrs More than 10 hours |
|
senior citizens ≥ 65 years |
7 - 8 hrs |
5 - 6 hrs 9 hours |
Less than 5 hrs More than 9 hours |
These figures are helpful guidelines, but do not reflect your personal sleep needs, which depend primarily on heredity--and are extremely influenced by your habits. So the best recipe for a restful sleep is to take care of your physical and mental well-being!
For more information, see an exciting TED Talk on the subject.