Baby Tylenol Dosage Chart: Safe Doses by Weight

The safe dose of baby Tylenol (acetaminophen) is 10 to 15 mg per kilogram of your baby's weight, given every 4 to 6 hours as needed, with at least 4 hours between doses. Use weight, not age, to find the right amount on the chart below. Give no more than 5 doses in 24 hours. For any baby under 12 weeks old with a fever, call your pediatrician before giving Tylenol. For any child under 2 years, the AAP and the Tylenol product label both recommend confirming the dose with your doctor before giving acetaminophen.

What Is Baby Tylenol (Infant Acetaminophen)?

Baby Tylenol is a brand-name pain reliever and fever reducer made for infants and children. The active ingredient is acetaminophen, also called paracetamol outside the United States. It is one of the most widely studied and commonly used medicines in pediatrics. Acetaminophen lowers fever and eases mild to moderate pain, and you can buy it over the counter without a prescription.

"Tylenol" is the most well-known brand name, but generic store-brand acetaminophen works just as well. The FDA requires every approved generic to contain the same active ingredient at the same concentration. There is no real difference in safety or how well it works between brand-name and generic.

Parents most often reach for baby Tylenol for fevers, teething pain, post-vaccination fussiness, and ear infection pain. It comes as a flavored liquid that you measure with an oral syringe.

When Can You Give a Baby Tylenol?

Acetaminophen is generally safe for babies 12 weeks (3 months) and older when given at the correct weight-based dose. Most pediatricians use the AAP guidance below.

A few common situations:

• Fever in babies 3 months and older. Acetaminophen can help your baby feel more comfortable, but the goal is comfort, not normal temperature. Treat the child, not the number.
• Post-vaccination fussiness. Some pediatricians recommend acetaminophen for babies as young as 8 weeks after a routine vaccine under your pediatrician's direction, and only if the baby develops a fever or seems uncomfortable. Routine prevention is not recommended (more on this in the FAQ).
• Teething pain. Acetaminophen is a safer choice than topical numbing gels for babies and toddlers (see FAQ).

Baby Tylenol Dosage Chart by Weight

The right dose of baby Tylenol depends on your child's weight. Always dose by weight first. Use age only if you do not know your child's current weight.

"Always dose acetaminophen by your child's weight, not their age. Weight-based dosing is the medical standard for safety, and it is also what the AAP chart and the product label both recommend."

Dr. Melissa Tribuzio, MD, Board-Certified Pediatrician

The standard concentration for all infant and children's liquid acetaminophen is 160 mg per 5 mL. This has been the single industry concentration since 2011, so older "concentrated infant drops" are no longer sold.

For babies under 12 weeks or under 6 lbs, do not give acetaminophen without your pediatrician. For any child under 2 years, confirm the dose with your doctor before giving.

How to Give Baby Tylenol Safely

Giving the right dose matters, but so does giving it the right way. A few habits prevent the most common mistakes.

• Use the oral syringe that comes with the product. Studies consistently show oral syringes are far more accurate than dosing cups for liquid medicine. Never use a kitchen spoon. Teaspoons and tablespoons are not precise enough and lead to dosing errors.
• Aim the syringe at the inside of the cheek. Give the liquid slowly, directing it toward the inside of your baby's cheek, not straight to the back of the throat. This prevents choking and helps the medicine go down.
• Wait at least 4 hours between doses, and 4 to 6 hours is the usual rhythm. Never give more than 5 doses in 24 hours.
• Store at room temperature (68°F to 77°F) and check the expiration date before every use.
• Keep all medicines out of reach. A child-resistant cap is not a substitute for safe storage. Toddler curiosity is a real overdose risk.

Infant Tylenol vs. Children's Tylenol: What's the Difference?

Infant Tylenol and Children's Tylenol are the same medicine at the same concentration: 160 mg of acetaminophen per 5 mL. This has been true since 2011.

The only real difference is the measuring device. Infant Tylenol comes with an oral syringe, which is more precise for the smaller doses babies need. Children's Tylenol comes with a dosing cup. That is why Infant Tylenol often costs 2 to 3 times more, because you are paying for the syringe, not a stronger medicine.

Before 2011, infant drops were about 3 times more concentrated than children's liquid. That caused dangerous dosing errors when parents accidentally switched between products. The FDA pushed the industry to a single standardized concentration to end those mistakes.

If you have Children's Tylenol at home and only need an infant dose, you can use it, as long as you measure with an oral syringe and dose by weight using the chart above. If you are unsure, message your pediatrician.

Can You Alternate Tylenol and Motrin (Ibuprofen)?

This is one of the most common questions parents ask, and the answer is more nuanced than you might expect.

The American Academy of Pediatrics (AAP) does not routinely recommend alternating acetaminophen and ibuprofen. The main concern is that switching between two medicines increases the chance of dosing errors, such as giving the wrong one, giving it too soon, or accidentally doubling up.

Some pediatricians do recommend a temporary alternating schedule (every 3 hours) for stubborn, high fevers that do not respond to one medicine alone. Research shows alternating can be modestly more effective at lowering the temperature, but it does not reduce side effects.

If your pediatrician recommends alternating:

• Remember that ibuprofen (Motrin) is not safe for babies under 6 months. Only acetaminophen is appropriate for infants under 6 months.
• Keep a written log of which medicine you gave and when. Phone notes work fine.
• Do not alternate for more than 24 hours without checking back with your doctor.

Common Baby Tylenol Questions

Here are the questions parents ask Blueberry pediatricians most often about giving their baby Tylenol.

When can I give my baby Tylenol for a fever?

For a baby 3 months (12 weeks) or older, you can give weight-based acetaminophen for a fever that is making your baby uncomfortable. The goal is comfort, not a normal temperature. For any baby under 3 months with a rectal temperature of 100.4°F or higher, do not give Tylenol. Call your pediatrician or seek care right away. Under 2 years, confirm the dose with your doctor before giving.

How much Tylenol can I give an 18-pound baby?

An 18-pound baby falls in the 18 to 23 lb (12 to 23 months) band on the dosing chart. The standard dose is 3.75 mL of 160 mg/5 mL liquid acetaminophen, given every 4 to 6 hours as needed, with no more than 5 doses in 24 hours. Because this is a child under 2 years, the AAP and the Tylenol product label both recommend confirming the dose with your pediatrician before you give it.

What's the Tylenol dose for a 4-month-old?

A 4-month-old baby is most often in the 12 to 17 lb band on the chart, depending on weight. The standard dose for that band is 2.5 mL of 160 mg/5 mL liquid acetaminophen every 4 to 6 hours as needed, up to 5 doses in 24 hours. Always dose by weight first. If your baby is heavier than 17 lb at 4 months, use the weight band that matches, and confirm with your doctor since this is under 2 years.

What's the mg-per-kg dose for infant Tylenol?

The standard dose of acetaminophen is 10 to 15 mg per kilogram per dose. Multiply your baby's weight in kg by 10 to 15 to get the milligram range, then convert to mL using the 160 mg per 5 mL concentration (divide the mg by 32 to get mL). The chart above already does this math for you for the standard infant and toddler weight bands.

How often can I give my baby Tylenol?

Every 4 to 6 hours as needed, with at least 4 hours between doses. Do not give more than 5 doses in any 24-hour period. If your baby still has a fever or pain after 24 hours of using Tylenol on a regular schedule, call your pediatrician, because it is time to be evaluated in person.

Can I give my newborn Tylenol?

Do not give acetaminophen to babies under 12 weeks without your pediatrician's explicit guidance. Any fever (rectal temperature of 100.4°F or higher) in a baby under 3 months requires immediate medical evaluation, not Tylenol at home.

How long does baby Tylenol take to work?

Liquid acetaminophen typically starts working within 30 to 45 minutes. You will usually see the peak effect about 1 to 2 hours after the dose.

What if my baby spits out or vomits the Tylenol?

If your baby vomits within 20 minutes of taking the dose, you can give another full dose. If more than 20 minutes have passed, wait and give the next dose at the regular 4-to-6-hour interval. Contact your pediatrician if vomiting continues.

Can Tylenol cause liver damage in babies?

Acetaminophen is safe at recommended weight-based doses. Liver damage is a risk of significant overdose, not from a single small measuring variance. That is why it is so important to never exceed 5 doses in 24 hours, to always dose by weight, and to check every other medicine for hidden acetaminophen. If you suspect your child has taken too much, call Poison Control (1-800-222-1222) right away.

Is generic acetaminophen as effective as brand-name Tylenol?

Yes. Generic acetaminophen contains the identical active ingredient at the same concentration. The FDA requires bioequivalence for every approved generic. There is no clinical difference.

Can I give baby Tylenol for teething?

Yes. Acetaminophen can ease teething pain, dosed by weight using the chart above. The AAP also recommends firm rubber teething rings and gentle gum massage. Avoid teething gels with benzocaine. The FDA warns against using these in children under 2 because of the risk of a serious condition called methemoglobinemia.

Is it safe to give baby Tylenol before vaccines?

The AAP does not recommend giving Tylenol before vaccines as a preventive. Research shows that pre-dosing acetaminophen can reduce the immune response, meaning the vaccine may not work as well. Give acetaminophen only after vaccination if your baby develops a fever or seems uncomfortable.

When to Call Your Pediatrician

Most fevers in children are harmless and resolve on their own. A few situations need a doctor's attention right away.

Call your pediatrician or seek care if:

• Your baby is under 3 months old and has any fever (100.4°F or higher, rectal).
• Your child has a fever above 104°F.
• The fever lasts more than 3 days despite treatment.
• You see signs of an allergic reaction: rash, swelling, or trouble breathing.
• Your child accidentally took too much. Call Poison Control at 1-800-222-1222 right away.
• Your child is unusually sleepy, will not stop crying, has a stiff neck, or shows other concerning symptoms.

"The primary goal of treating a febrile child should be to improve the child's overall comfort rather than focus on normalization of body temperature."

American Academy of Pediatrics

Fever is your child's immune system at work. Treat the discomfort, not the number on the thermometer.

References

1. Sullivan JE, Farrar HC; AAP Section on Clinical Pharmacology and Therapeutics, Committee on Drugs. "Fever and Antipyretic Use in Children." Pediatrics. 2011;127(3):e20103852.
2. American Academy of Pediatrics, HealthyChildren.org. "Acetaminophen Dosing Tables for Fever and Pain in Children." Updated 2025.
3. American Academy of Pediatrics. "How to Give the Right Amount of ACETAMINOPHEN: Pictographic Dosing Chart." HealthyChildren.org / downloads.aap.org.
4. Tylenol (manufacturer). "Dosing Chart for Children & Infants."
5. FDA Drug Safety Communication. "Addition of another concentration of liquid acetaminophen marketed for infants." December 22, 2011.
6. University Hospitals Rainbow Babies & Children's. "Acetaminophen/Tylenol Dosage Table."
7. Prymula R, Siegrist CA, Chlibek R, et al. "Effect of prophylactic paracetamol administration at time of vaccination on febrile reactions and antibody responses in children." The Lancet. 2009;374(9698):1339-1350.
8. De la Cruz-Mena JE, Florez ID, et al. "Short-term Dual Therapy or Monotherapy With Acetaminophen and Ibuprofen for Fever: A Network Meta-Analysis." Pediatrics. 2024;154(4):e2023065390.
9. Temple AR, et al. "Comparison of the Efficacy and Safety of 2 Acetaminophen Dosing Regimens in Febrile Infants and Children."
10. Pantell RH, et al. "Clinical Practice Guideline: Evaluation and Management of Well-Appearing Febrile Infants 8 to 60 Days Old." Pediatrics. 2021;148(2):e2021052228.
11. FDA. "Safely Soothing Teething Pain and Sensory Needs in Babies and Older Children." FDA Safety Communication, 2018.

This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your child's pediatrician or qualified healthcare provider with any questions about your child's health. If you think your child may have a medical emergency, call your doctor or 911 immediately.