Infant Tylenol and Motrin Dosage by Weight
Dose by weight, not age. The right amount depends on what your baby weighs and which medicine you are using.
Two medicines treat fever and pain in babies: acetaminophen (Tylenol) and ibuprofen (Motrin, Advil). The correct dose is based on weight, not age. Ibuprofen is only for babies 6 months and older. The AAP advises that acetaminophen not be given to a child under 2 years without a doctor's guidance, and a fever in a baby under 3 months needs to be checked before any medicine is given. This page gives the weight-based dosing the American Academy of Pediatrics publishes, how often each medicine can be given, and the safety rules that keep a dose from becoming an overdose. For any child under 2 years, confirm the exact dose with your pediatrician or pharmacist first.
Reviewed against current AAP, CDC and federal guidance
The rule that matters most: dose by weight
Two children the same age can weigh very different amounts, so age alone gives the wrong dose. Use your baby's current weight. The charts below also list an age range as a rough guide, but weight wins when the two disagree. Acetaminophen liquid is sold as 160 mg per 5 mL. Ibuprofen comes in two strengths: infant drops at 50 mg per 1.25 mL and children's liquid at 100 mg per 5 mL. Doses are not interchangeable between them. Read the concentration on the bottle you are holding, and measure with the oral syringe or dosing cup that came with that product. A kitchen spoon is not a dosing tool. The AAP advises that acetaminophen not be given to a child under 2 years without a doctor's guidance, so for any child under 2 years contact your pediatrician or pharmacist for the correct dose before giving the first dose.
Which medicine, and from what age
- Under 2 years: the AAP advises not to give acetaminophen without your doctor's guidance. Confirm the exact dose with your pediatrician or pharmacist.
- Under 3 months (12 weeks): do not give any fever medicine on your own. A fever in the first 12 weeks can signal a serious infection and needs to be checked. Call the doctor first.
- Give every 4 hours while symptoms last. Do not give more than 5 doses in 24 hours.
- Liquid is 160 mg per 5 mL. Check the bottle.
Used at the right weight-based dose and spacing, acetaminophen is a long-established medicine for infant fever and pain.
- Do not use in a baby under 6 months unless the doctor tells you to.
- Give it with food or milk to be gentler on the stomach.
- Give every 6 to 8 hours if needed. Do not give more than 4 doses in 24 hours.
- Infant drops are 50 mg per 1.25 mL. Children's liquid is 100 mg per 5 mL. Check which one you have.
- Under 2 years: confirm the exact dose with your pediatrician or pharmacist.
Once your baby is 6 months or older, ibuprofen is a second option. Many families keep one medicine on hand and use it as directed rather than switching back and forth.
- Do not give aspirin to a baby, child, or teen.
- Aspirin in children is linked to Reye syndrome, a rare but serious illness affecting the liver and brain.
- Check combination cold and flu products: some contain aspirin or salicylate. Read every ingredient.
This is a firm line, not a judgment call. For fever and pain in children, the choices are acetaminophen and, from 6 months, ibuprofen.
Acetaminophen (Tylenol) dose by weight
| Weight | Age (guide only) | Dose (160 mg/5 mL liquid) | Dose in mg |
|---|---|---|---|
| 6–11 lb (2.7–5 kg) | 0–3 months | Ask the doctor | Ask the doctor |
| 12–17 lb (5–7 kg) | 4–11 months | 2.5 mL | 80 mg |
| 18–23 lb (8–10 kg) | 12–23 months | 3.75 mL | 120 mg |
| 24–35 lb (11–15 kg) | 2–3 years | 5 mL | 160 mg |
| 36–47 lb (16–21 kg) | 4–5 years | 7.5 mL | 240 mg |
| 48–59 lb (22–26 kg) | 6–8 years | 10 mL | 320 mg |
| 60–71 lb (27–32 kg) | 9–10 years | 12.5 mL | 400 mg |
| 72–95 lb (33–43 kg) | 11 years | 15 mL | 480 mg |
Ibuprofen (Motrin, Advil) dose by weight
| Weight | Age (guide only) | Infant drops (50 mg/1.25 mL) | Children's liquid (100 mg/5 mL) | Dose in mg |
|---|---|---|---|---|
| Under 12 lb (under 5 kg) | Under 6 months | Ask your doctor | Ask your doctor | Not for use under 6 months without a doctor |
| 12–17 lb (5–7 kg) | 6–11 months | 1.25 mL | 2.5 mL | 50 mg |
| 18–23 lb (8–10 kg) | 12–23 months | 1.875 mL | 3.75 mL | 75 mg |
| 24–35 lb (11–15 kg) | 2–3 years | 2.5 mL | 5 mL | 100 mg |
| 36–47 lb (16–21 kg) | 4–5 years | 3.75 mL | 7.5 mL | 150 mg |
| 48–59 lb (22–26 kg) | 6–8 years | 5 mL | 10 mL | 200 mg |
| 60–71 lb (27–32 kg) | 9–10 years | Use children's liquid | 12.5 mL | 250 mg |
| 72–95 lb (33–43 kg) | 11 years | Use children's liquid | 15 mL | 300 mg |
How to give a dose safely
- Weigh first. Use your baby's current weight to pick the band, not age.
- Read the concentration on the bottle. Confirm it is 160 mg/5 mL acetaminophen, or which ibuprofen strength you have.
- Measure with the oral syringe or dosing cup that came with that product. If there is none, ask your pharmacist for one. Never use a kitchen spoon.
- Never exceed the dose or frequency on the label: acetaminophen no more than 5 doses in 24 hours, ibuprofen no more than 4.
- Do not give two products that contain the same drug. Many cold, flu, and cough medicines already contain acetaminophen or ibuprofen. Read every ingredient before combining anything.
- Avoid multi-ingredient cough and cold medicines in children under 6 years.
- Write down each dose with the time. If two caregivers are involved, this prevents an accidental double dose.
- Do not alternate acetaminophen and ibuprofen on your own. If you think your child needs it, ask the doctor for a specific plan first.
Suspected overdose or a medicine mistake
- Get poison help right away: call 1-800-222-1222 or use the online tool at poison.org. Both are free and confidential, and they will tell you exactly what to do.
- Keep the bottle with you so you can read the concentration and how much was given.
- If your child is unconscious, not breathing, seizing, or you cannot wake them, call 911 first.
Call your pediatrician now
- Your baby is younger than 3 months (12 weeks) and has a rectal temperature of 100.4°F (38°C) or higher. This needs to be checked before you give any medicine.
- Your child is under 2 years and the fever lasts more than 24 hours.
- Your child is 2 years or older and the fever lasts more than 3 days (72 hours), or the fever goes away and then returns.
- Any child whose temperature repeatedly rises above 104°F (40°C).
- Your child is under 2 years and you are unsure of the correct dose.
- Your child seems very ill, is hard to wake, will not drink, has no wet diapers, or has trouble breathing.
- A rash appears with the fever, or your child has a stiff neck or a seizure.
- You think you may have given the wrong medicine or the wrong amount.
Quick answers
- Should I dose infant Tylenol by weight or by age?
- By weight. Two babies of the same age can weigh very different amounts, so age alone gives the wrong dose. Use your baby's current weight to find the band on the chart. Acetaminophen liquid is 160 mg per 5 mL, and the dose is given every 4 hours with no more than 5 doses in 24 hours. The AAP advises not to give acetaminophen to a child under 2 years without a doctor's guidance, so confirm the exact dose with your pediatrician or pharmacist first.
- Can I give Tylenol to a baby under 3 months old?
- Not on your own. A fever in the first 12 weeks can signal a serious infection. If a baby younger than 3 months has a rectal temperature of 100.4°F (38°C) or higher, call the doctor right away and do not give any fever medicine until you are told to. The fever itself needs to be evaluated, not just treated. The AAP also advises that acetaminophen not be given to any child under 2 years without a doctor's guidance.
- When can babies have ibuprofen (Motrin or Advil)?
- From 6 months of age. Do not give ibuprofen to a baby under 6 months unless the doctor specifically tells you to. From 6 months, dose by weight: infant drops are 50 mg per 1.25 mL and children's liquid is 100 mg per 5 mL, so check which one you have. Give it every 6 to 8 hours if needed, with no more than 4 doses in 24 hours, and give it with food or milk.
- Can I give Tylenol and Motrin at the same time?
- Do not combine or alternate them on your own. They are different drugs, so giving both at once is not the same as a double dose of one, but switching back and forth makes dosing errors easy and is not needed for most fevers. Never give two products that contain the same drug, since many cold and flu medicines already include acetaminophen or ibuprofen. If you think your child needs a combined plan, ask the pediatrician for specific instructions first.
- Why can't children take aspirin for fever?
- Aspirin in babies, children, and teens is linked to Reye syndrome, a rare but serious illness that affects the liver and brain. For fever and pain in children, use acetaminophen, and from 6 months ibuprofen. Read the ingredients on any combination cold or flu product, because some contain aspirin or salicylate under another name.
- What do I do if my baby gets too much fever medicine?
- Get poison help right away: call 1-800-222-1222 or use the online tool at webPOISONCONTROL (poison.org). Both are free and confidential, and they will tell you exactly what to do. Keep the bottle with you so you can read the concentration and how much was given. If your child is unconscious, not breathing, seizing, or you cannot wake them, call 911 first.
- What kind of syringe should I use to measure the dose?
- Use the oral dosing syringe or cup that came with that specific product. It is matched to the medicine's concentration, and an oral syringe measures small liquid amounts far more accurately than a kitchen spoon. If your product did not come with one, ask your pharmacist for a proper dosing syringe rather than estimating.
Sources & further reading
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App Store Google Play Open Web AppThis guide reflects current AAP, CDC and federal guidance and is for educational purposes only. It does not constitute medical or legal advice. ParentFlow is a wellness companion — not a substitute for your pediatrician. For any medical concern, contact your healthcare provider.