What is the right doses of childrens tylenol (acetaminophen) and/or Advil for a 9 months, 20 pounds baby?

Use a calculator. First change the weight into kilograms. You take the weight in pounds, 20 divided by 2.2 which is 9. Always divide the weight in pounds by 2.2 tylenol (acetaminophen) dose is 15 x 9=135mg every 4 hours. It usually comes in 80mg per tsp. A tsp is 5 ml. So 1 ml would be 20mg, so 8 1/2 ml would be 135mg. Ibuprofen is 5 x9=45mg every 6 hours. It comes in 100mg per 5ml so each ml is 20mg so 45mg would be 2 1/4 ml.
1/2 tsp,2.5ccTylenol. For 20# (9 kg) the correct dose should be ~ 80-90 mg which is about 1/2 tsp or 2.5 ml of the liquid. 'children's motrin' dosing is @ http://www.Theodora.Com/drugs/childrens_motrin_dosing_chart_mcneil_consumer.Html .