An adult needs around 8 hours of sleep minimum for best health and to feel rested the next day.
Some people get 5 to 6 hours of sleep which is better than no sleep at all but if possible try to get at least 8 hours of sleep per night.
On workdays I try to get at least 8 hours of sleep which I normally do and then on the weekends when I don't have to work I try to get 9 to 10 hours of sleep to help catch up on the sleep which makes me feel better.
Sleep is very important to good health so always try to get as much sleep as possible.