Diphenhydramine (Benadryl) Dosage

Child's Weight (pounds)20-2425-3738-4950-99100+lbs
Liquid 12.5 mg/ 5 milliliters (mL)457.510-mL
Liquid 12.5 mg/ 1 teaspoon (tsp)3/411 1/22-tsp
Chewable 12.5 mg-11 1/224tabs
Tablets 25 mg-1/21/212tabs
Capsules 25 mg---12caps

When to Use: treatment of allergic reactions, nasal allergies, hives and itching

Caution: If you have questions, call your child’s doctor.

Always check the concentration on the label before using this dose table.


  • Age Limits: For allergies, don’t use under 1 year of age.  It should not be given if under 6 months old.
  • Reason: It causes most babies to be too sleepy (dangerously so). For colds, not advised at any age, because there are no proven benefits.


  • Dose: Find the child’s weight in the top row of the dose table. Look below the correct weight for the dose based on the product you have.
  • Measure the Dose: Always use syringes and droppers for liquid medication (teaspoons vary too much, and could lead to incorrect dosing). If possible, use the syringe or dropper that comes with the medicine. If not, you can get a med syringe at a drug store. If you use a teaspoon, it should be a measuring spoon. Reason: regular spoons are not reliable. Keep in mind 1 level teaspoon equals 5 mL and that ½ teaspoon equals 2.5 mL.
  • Adult Dose: 50mg
  • How Often for Under 6 Years: Repeat every 6-8 hours as needed. (Exception: do not use under 1 year unless directed by provider.)
  • How Often for 6 Years and Older: Repeat every 4-6 hours as needed.
  • Brand Names: Benadryl, generic diphenhydramine
  • Children’s Benadryl Fastmelts: Each Fastmelt tablet equals 12.5mg. They are dosed the same as chewable tablets.
  • Use in Countries Outside the U.S.: Dose tables are based on U.S. products. Concentrations may vary in countries outside the U.S.
Disclaimer:  This web site is meant to provide reliable information consistent with the standard of care at the time of publication. It is not designed to be all inclusive nor is it intended to substitute for the individual advice and decision-making provided by your pediatrician. Andrew Elliston MD, and Elliston Pediatrics, therefore, takes no responsibility for the all inclusive accuracy and content of these pages or that of links from these pages.

This website and all its content is being provided for information and education purposes only. No doctor/patient relationship has been established by the use of this site, nor is any diagnosis or treatment being provided hereby. The information contained herein is not intended to substitute for professional medical advice, diagnosis or treatment, and should only be used in consultation with a pediatrician.  Consequently, neither Andrew Elliston MD or Elliston Pediatrics take any responsibility for the accuracy and content of these pages or for web sites hyperlinked to this site and such hyper-linking does not imply any relationship or endorsement to the linked sites.  Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition, and never disregard professional medical advice or delay in seeking it because of something you have read on this site. If you think you may have a medical emergency, call your doctor or 911 immediately.

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