Adults and children 12 years and over should take 2 tablets, caplets, gelcaps or tablespoons every 4 to 6 hours as needed -- with no more than 8 tablets, caplets, gelcaps or tablespoons in 24 hours. Extra strength Tylenol should not be taken for more than 10 days unless directed by a doctor. It must be emphasized -- you should take no more than 8 extra strength Tylenol per day. The maximum allowable daily dose of Tylenol (acetaminophen) is 4 grams (or 4,000 mg) in adults and 90 mg/kg in children. Do the math -- 8 times 500 mg equals 4,000 mg -- the daily maximum you can safely take.