8-10 hours since this is the age we go threw all our growth spurs. So sleep is very important, and since our bodies are changing everyday it weakens the body more which makes us sleepy. And parents get mad for us sleeping a lot haha(:
Teenagers need a minimum of 8-9 hours of sleep every night. 9-10 hours is better because the brains of teenagers are still developing and growing, and if teens don't get enough sleep, it can affect brain growth.