i dont think it is...depending on your age...
people 14 and up should get at a minimum of 8 hours of sleep a night
people ages 8-13 should get 9+ hours of sleep
and people ages 7- should get 10+ hors of sleep a night
what do you eat befor bed? if you have any caffine (chocolate, sodas, candy) that will keep you up, not only becaus eofd the caffine, but because of the sugars.
if you cant seem to get more than the amount of sleep your getting now, you should talk to a doctor about this problem, and they could put you on a sleep medication. or if youre younger (like me) just tell your parents and let them deal with the situation.
hope this helped and good luck!