Children's Benadryl Dosage Chart by Weight
Diphenhydramine (Children's Benadryl) is an older, sedating antihistamine. It works for hives and itchy allergic reactions, but the label limits its use in young children and it should never be used as a sleep aid. Here is what the label says, the weight-based doses pediatricians use, and when a different medicine is a better choice.
Age limits on the Children's Benadryl label
- Under 2 years: do not use.
- 2 to 5 years: do not use unless directed by a doctor.
- 6 to 11 years: 5 mL to 10 mL every 4 to 6 hours, no more than 6 doses in 24 hours.
- Do not use to make a child sleepy, and do not combine with any other diphenhydramine product, including creams.
Benadryl dosage chart by weight
When we direct a dose for a child, we choose it by weight. The table below shows typical doses for Children's Benadryl liquid (12.5 mg per 5 mL) and 12.5 mg chewable tablets. Give it every 6 hours as needed, unless we tell you otherwise.
| Weight | Typical age | Children's liquid (12.5 mg / 5 mL) | Chewable (12.5 mg) |
|---|---|---|---|
| 25 to 37 lbs | 2 to 5 years* | 5 mL (12.5 mg) | 1 tablet |
| 38 to 49 lbs | 4 to 6 years* | 7.5 mL (18.75 mg) | 1½ tablets |
| 50 to 99 lbs | 6 to 11 years | 10 mL (25 mg) | 2 tablets |
| 100 lbs or more | 12 years or older | 20 mL (50 mg) | 4 tablets |
If you prefer to enter a weight, our pediatric dose calculator uses the weight bands above for children 6 and older. For younger children, call us rather than estimating a dose.
When Benadryl helps, and when something else is better
- Hives and mild allergic reactions: diphenhydramine works within about 30 to 60 minutes. For hives that last more than a day, a once-daily non-drowsy medicine is often easier. See our Zyrtec and Claritin dosing guide.
- Seasonal allergies: cetirizine or loratadine once a day usually controls symptoms with less drowsiness and no need for repeat doses.
- Colds and coughs: antihistamines do not help colds in children. The AAP and FDA advise against cough and cold medicines for young children.
- Sleep: never. Some children become agitated or hyperactive instead of sleepy.
Safety warnings
In 2020 the FDA warned that taking higher than recommended doses of diphenhydramine can cause serious heart problems, seizures, coma, or death, after reports of teenagers taking large amounts in online challenges. Store all antihistamines up high and out of sight, and keep track of how much is left in the bottle.
Side effects at normal doses can include drowsiness, dry mouth, dizziness, and in some children restlessness or excitability.
Call 911 or go to the nearest ER if your child:
- Has trouble breathing, wheezing, or throat tightness
- Has swelling of the lips, tongue, or face
- Vomits repeatedly or seems faint after eating a food or getting a sting
- Took more diphenhydramine than directed and is very sleepy, confused, or has a fast heartbeat (or call Poison Control at 1-800-222-1222)
Questions About Allergy Medicine?
Call us before giving diphenhydramine to a child under 6, or if your child has hives that keep coming back. Our eczema and allergy care visits help find the trigger and the right daily plan.
Call us at (609) 808-3123 during office hours:
- Monday to Friday: 9:30 AM to 5:30 PM
- Saturday: 9:30 AM to 12:30 PM
Common Questions from Parents
How much Children's Benadryl can I give my child?
The label dose for children 6 to 11 years is 5 to 10 mL of children's liquid (12.5 mg per 5 mL) every 4 to 6 hours, with no more than 6 doses in 24 hours. Pediatricians usually choose the dose by weight; for example, a child who weighs 50 to 99 pounds typically takes 10 mL. For children 2 to 5, the label says to use it only if a doctor tells you to.
Can I give Benadryl to my 1-year-old or 2-year-old?
The label says not to use Children's Benadryl under age 2, and to use it from 2 to 5 only when a doctor directs. If your toddler has hives or an allergic reaction, call us so we can recommend the right medicine and dose. Many families do better with a non-drowsy antihistamine, which we can also dose for you.
Is it safe to give Benadryl to help my child sleep?
No. The label specifically says not to use it to make a child sleepy. Diphenhydramine can cause agitation instead of sleep in some children, and high doses can cause serious heart problems, seizures, and coma. Talk with us about sleep concerns instead.
What is the diphenhydramine dose in mg per kg for children?
A common pediatric reference dose is about 1.25 mg per kg per dose, up to 50 mg per dose. The chart and calculator use weight bands for measurable doses, with age restrictions. Do not calculate a dose yourself for a child under 6.
Should I give Benadryl for a severe allergic reaction?
No, not as the main treatment. If your child has trouble breathing, swelling of the lips or tongue, repeated vomiting after a food, or seems faint, use their epinephrine auto-injector if they have one and call 911. Antihistamines do not stop anaphylaxis.
Sources
- DailyMed: Children's Benadryl Allergy (diphenhydramine) Drug Facts label (accessed October 26, 2026)
- St. Louis Children's Hospital: Diphenhydramine (Benadryl) Dose Table (Schmitt Pediatric Guidelines) (accessed October 26, 2026)
- HealthyChildren.org (AAP): Allergy Medicine for Children
- U.S. FDA: Serious problems with high doses of diphenhydramine (Benadryl) (September 24, 2020)