There is a pediatric dosing chart for Children's Tylenol on Medscape's website. Users should base the Tylenol dosage on the child's weight, using 10 to 15 milligrams for each kilogram as the dose, according to Medscape. It is possible to use the chart if the child's weight is unknown.
Tylenol should be given every four to six hours, and the child should not consume more than five doses in one day, reports Medscape. For infants between 0 and 3 months who weigh between 6 and 11 pounds, 40 milligrams of Tylenol should be given. The dosage in milligrams increases as the child's age and weight increases.