How long does it take for a 5 year old to go to sleep?

Studies show that usually kids between 3-5 years old need about 12 hours of sleep, and kids between 5-10 years usually need 10 hours of sleep. So a 5 year old should go to sleep about 11 hours before he/she wakes up. (Maybe a little bit more, because the wont fall asleep promptly after going to bed.)