what dosage of Benadryl for a 30 pound/ 2 year old toddler? At 8 months-old my son was prescribed Q-Dryl 1 ml every 6 hours. Benadryl Dosage Chart Benedryl Liquid 12.5 mg/5mL (tsp) Benedryl Chewable. 25 mg Weight Teaspoon (tsp) Chewables Capsule 22 to 32 pounds ¾ tsp - - 33 to 43 pounds. For the oral form of Benadryl, dosage recommendations range from 25 to 50 mg every four to six hours. This eMedTV Web page also includes dosing information for. Benadryl is useful for the relief of allergic symptoms. Milligram Dosage. 28-32 lbs: 15.625mg: 1 1/4 tsp (6.25ml) N/A: 33-38 lbs: 18.75mg: 1 1/2 tsp (7.5ml) N/A: Related questions How Much Benadryl Can I Give To a 2 Year Old That Weighs 26 Pounds? how much to give a 2 year old of diphenhydramine HCI who weighs 35 pounds St. Louis Children’s Hospital provides a Diphenhydramine (Benadryl - Allergy Medicine) Dosage Table for determining the amount of allergy medicine to give a child. What's the Benadryl dosage for toddlers?. of liquid Benadryl has 12. 5 mg. (or weighing between 24-35 lbs) the dosage is ¾ tsp. Please Help-Dosage of Children's Benadryl for almost 4 year old wighing 38 pounds - Welcome to Circle of Moms!!.