Benadryl Dosage Calculator

Created by Joanna Michałowska, PhD candidate and Aleksandra Zając, MD
Reviewed by Dominik Czernia, PhD and Jack Bowater
Based on research by
Benadryl Dosing Guide (2022)
Last updated: Jun 05, 2023

The Benadryl dosage calculator recommends how much Benadryl you should take yourself or give to your little one. Check the article below to find out more about Benadryl dosage for kids and for adults, what the active ingredient in Benadryl is, and what are the side effects of this medication.

Interested in other dosing calculators 💊? We have created tools such as the ibuprofen dosage calculator to make sure you will always pick the proper dose to administer. Other tools for medications include Aleve dosage, and infant Tylenol dosage calculator.

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace professional medical advice.

What is Benadryl used for?

Benadryl is a brand name which includes several antihistamine medications to stop allergies.

They relieve symptoms due to hay fever and other upper respiratory allergies:

  • Runny nose;
  • Sneezing;
  • Itchy and watery eyes;
  • Itching of the nose or throat; and
  • Symptoms of the common cold such as runny nose and sneezing.

Diphenhydramine is the main active ingredient in Benadryl. Sometimes, other active ingredients are added, for example, phenylephrine (in Children’s Benadryl Allergy Plus Congestion) relieves the symptoms of nasal congestion.

Benadryl dosage calculator - how does it work?

Are you tired of checking Benadryl dosage charts and figuring out "How much Benadryl can I take?" Don't worry - we have created Benadryl dosage calculator for you.

Using Benadryl dosage calculator could not be easier:

  1. Enter your age.
  2. Choose the Benadryl product you are interested in.

That's it. In the results section, you will see the recommended Benadryl dosage.

➡️ If you were advised by the vet to give Benadryl to your dog, check our Benadryl dosage for dogs calculator.

Benadryl side effects

Just like with any other medications, using Benadryl may be associated with some side effects.

The most common Benadryl side effects (occurring in between 1 and 10% of patients) include:

  • Drowsiness;
  • Dizziness;
  • Sleepiness;
  • Headache; and
  • Attention disturbance.


What is Benadryl challenge? Benadryl overdose

Benadryl challenge is a new term, which describes a trend on the social media app TikTok. It emerged in 2020 and dares users to take high doses of Benadryl to induce hallucinations, and then film themselves to show the effects of the Benadryl overdose. This phenomenon is extremely dangerous and can lead to serious health problems, including seizures, heart problems, coma, and death.

To learn more, read the FDA's warning regarding the Benadryl challange and TikTok's community guideline.

❗❗ Remember to always take medicine as directed - follow your doctor's advice and/or the instructions on the label.

Benadryl dosage for adults

As mentioned above, you should always follow the information on the label when taking Benadryl, unless instructed otherwise by a health professional.

The recommended Benadryl dosage for adults is 1 to 2 tablets, depending on the type of medication. Use our Benadryl dosage calculator to find out more.

Children's Benadryl dosage

If you want to administer Benadryl to your child, please remember:

  • Benadryl Allergy ULTRATAB Tablets and LIQUI-GELS should not be given to children under 6 years of age.
  • Do not give Benadryl Extra Strength Allergy ULTRATAB tablets to children under 12 years old.
  • You need to ask a doctor if you want to give Benadryl Allergy Plus Congestion to children under 12 years of age.
  • Children’s Benadryl Allergy Liquid, Children’s Benadryl Allergy Plus Congestion, and Children’s Benadryl Chewables are intended for children; however, you should consult your doctor before giving them to children under 6 years of age.
Joanna Michałowska, PhD candidate and Aleksandra Zając, MD
Medication type
Benadryl® Allergy ULTRATAB
🧐 This medication temporarily relieves the symptoms of hay fever and other upper respiratory allergies: runny nose, sneezing, itchy and watery eyes, itching of the nose or throat, as well as symptoms of the common cold such as runny nose and sneezing.
⚕️ Administer a maximum of 6 doses over 24 hours.
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