how many hours sleeping are enough for you?(you want to wake up)(*maybe i have done a grammar mistake)
or better how many hours do you need to sleep?or how many hours are enough to be able to feel good when you wake up?
or how many hours are necessary to you to be able to wake up without troubles? how many hours are enough to be able to feel good when you wake up after slept(or have slept?)?

Question

how many hours sleeping are enough for you?(you want to wake up)(*maybe i have done a grammar mistake)
or better how many hours do you need to sleep?or how many hours are enough to be able to feel good when you wake up?
or how many hours are necessary to you to be able to wake up without troubles?   how many hours are enough to be able to feel good when you wake up after slept(or have slept?)?

Answer

Depends on the day... if your day was pretty calm and you have your batteries charged you don't need to sleep too much and you probably won't ! But if your day was one of thooose days when you exchange pretty words with the clock because there's not enough time, you will need to rest a little bit more. 
In general 6 hours of deep sleep are fine, but each person is his/her own expert, you should know about you! 
=D

Answer

How many hours of sleep are enough for you?
or
How many hours of sleeping is enough for you?

Maybe I have made a grammar mistake.

Answer

it depends( in the study period 5-6 hours ( Normal days without exams ) but in exams cuz I can't sleep so 2 hours is enough for me xD  - and in the holidays of course more than 6 hours hehe xD

Answer

I add in an afternoon nap right after work, so I'm guaranteed at least 8 or more hours a day.  Plus I'm full of energy in the evenings!

Also, I believe it is possible to sleep too much, and therefore "sleep yourself tired".  So there must be a limit to how much you should sleep?

Answer

I need 10 hrs, but I only get 8 :(