Zyrtec Child Dosage Chart: Weight-Based Cetirizine Dosing for Parents

By Kurt Hansen, MD · Emergency Physician

Cetirizine (Zyrtec) is a once-daily, second-generation antihistamine used to relieve common allergy symptoms — sneezing, runny nose, itchy or watery eyes, and itchy skin from hives. It is less sedating than older antihistamines like diphenhydramine, and most kids tolerate it well for the full 24-hour dosing window. Because allergy symptom relief is the goal, dosing should be consistent rather than "only when needed." Cetirizine is only for children 12 months and older; younger infants should not be given it.

The calculator below uses the standard 0.25 mg/kg pediatric cetirizine dose (maximum 10 mg per single dose, once per 24 hours). Enter your child's weight, confirm the formulation you have at home, and the calculator returns the exact mL for the Children's Zyrtec (cetirizine) 5 mg / 5 mL syrup in front of you.

Calculate your child's Zyrtec dose

How Perfect Dose calculates doses — FAQ

Looking for generic cetirizine dosing instead of a brand-specific chart? See our Cetirizine Child Dosage Chart.

About the Author

Kurt Hansen, MD, is an Emergency Physician and the founder of Perfect Dose App. He has counseled thousands of parents on pediatric medication dosing during more than a decade of emergency medicine practice.