This guide covers Tylenol and ibuprofen dosing by weight, when each medicine may be used, and when a fever needs immediate evaluation.
If your baby is under 12 weeks old, read this first
A rectal temperature of 100.4°F (38°C) or higher in a baby under 12 weeks of age requires immediate medical evaluation.
Record the rectal temperature and the time, and go to the nearest emergency department. Do not give acetaminophen (Tylenol) before speaking with a clinician unless a clinician has already given you specific instructions. Medication must never delay evaluation.
At this age a fever can be the only outward sign of a serious infection, which is why being seen comes first.
Treating discomfort, not a number
For older infants and children, fever is not the thing being treated. Fever is part of how a body fights infection, and a child who is drinking, playing and reasonably comfortable does not need medicine simply because a thermometer reads high.
These medicines are for discomfort such as aching, misery, difficulty settling or sleeping. If your child is comfortable, it is reasonable to give nothing and watch.
When can a baby have acetaminophen (Tylenol)?
Acetaminophen (Tylenol) should not be given to children under two years of age without guidance from their clinician. For children two and over, the amount follows current weight, using the table below.
When can a child have ibuprofen (Motrin, Advil)?
Ibuprofen is not used in infants under 6 months unless your child’s clinician has specifically directed it.
Do not give ibuprofen to a child who is significantly dehydrated, drinking poorly, or vomiting repeatedly, without speaking to us first. Dehydration can increase the risk of kidney injury from ibuprofen.
Check the concentration on your bottle first
Since 2011, infant and children’s liquid acetaminophen (Tylenol) in the United States are both 160 mg per 5 mL. Older bottles, imported products, chewables and combination products differ, and the tables below apply only to the concentrations named in them.
Use the syringe or cup that came with that bottle. An oral syringe is the most accurate way to measure liquid medicine; kitchen spoons are not accurate.
Check cold and flu medicines before you dose
Many combination cold, flu, cough and sinus products already contain acetaminophen or ibuprofen. Giving one of those alongside a separate dose is a common cause of accidental overdose.
Read the active ingredients on every product. If it lists acetaminophen, paracetamol, APAP, ibuprofen or NSAID, do not add a separate dose without talking to us. The AAP advises against multi-ingredient medicines altogether for children under 6.
Acetaminophen (Tylenol) dosing by weight: liquid, 160 mg / 5 mL
Children under age 2 should receive acetaminophen only with clinician guidance. The amounts below do not replace that guidance.
| Weight | Age | Volume |
|---|---|---|
| Any weight | Under 12 weeks | Do not dose. Go to the nearest emergency department. |
| 12–17 lb (5–7 kg) | 4–11 months | 2.5 mL (under 2, clinician guidance) |
| 18–23 lb (8–10 kg) | 12–23 months | 3.75 mL (under 2, clinician guidance) |
| 24–35 lb (11–15 kg) | 2–3 years | 5 mL |
| 36–47 lb (16–21 kg) | 4–5 years | 7.5 mL |
| 48–59 lb (22–26 kg) | 6–8 years | 10 mL |
| 60–71 lb (27–32 kg) | 9–10 years | 12.5 mL |
| 72–95 lb (33–43 kg) | 11 years | 15 mL |
If your child’s current weight is not listed, do not estimate, round to another row or extend the table. Contact your clinician or pharmacist.
Give only as needed, with at least 4 hours between doses. Do not give more than 5 doses in 24 hours.
For children age 12 and older or weighing 96 lb or more, follow the specific product label or ask your clinician or pharmacist. Do not calculate a liquid dose by extending this table.
Ibuprofen dosing by weight: Children’s Liquid Ibuprofen, 100 mg / 5 mL
| Weight | Age | Volume |
|---|---|---|
| 0–11 lb (up to 5 kg) | 0–5 months | Do not use unless specifically directed by your child’s clinician |
| 12–17 lb (6–7 kg) | 6–11 months | 2.5 mL |
| 18–23 lb (8–10 kg) | 12–23 months | 4 mL |
| 24–35 lb (11–15 kg) | 2–3 years | 5 mL |
| 36–47 lb (16–21 kg) | 4–5 years | 7.5 mL |
| 48–59 lb (22–26 kg) | 6–8 years | 10 mL |
| 60–71 lb (27–32 kg) | 9–10 years | 12.5 mL |
| 72–95 lb (33–43 kg) | 11 years | 15 mL |
| 96 lb or more (44 kg+) | 12 years or older | 10 mL + 10 mL = 20 mL (Children’s Liquid Ibuprofen, 100 mg / 5 mL) |
If your child’s current weight is not listed, do not estimate, round to another row or extend the table. Contact your clinician or pharmacist.
Give every 6 to 8 hours as needed. Do not give more than 4 doses in 24 hours.
Infant ibuprofen drops are more concentrated (50 mg per 1.25 mL). If you are using drops, use the chart on that package, not this one.
Why we dose by weight and not by age
Two children the same age can differ substantially in weight, and the safe amount follows the body, not the birthday. This matters most in the first two years, when weight changes fast enough that a dose which was right two months ago may now be too small. Weigh-ins at well visits are where we update this.
Do not alternate or combine without being told to
Do not alternate acetaminophen and ibuprofen, or give both, unless we have specifically directed it for your child. Alternating doubles the chances of a timing or measuring error and is usually unnecessary.
If you think your child has had too much
Call Poison Control at 1-800-222-1222 immediately, 24 hours a day, free and confidential. Do not wait for symptoms; acetaminophen overdose often causes none at first. If your child is unresponsive, having difficulty breathing, or having a seizure, call 911.
Common questions from parents
Can a 2-month-old have Tylenol?
In a baby under 12 weeks, a rectal temperature of 100.4°F (38°C) or higher requires immediate medical evaluation. Record the temperature and time and go to the nearest Emergency Department. Do not give acetaminophen or ibuprofen first unless a clinician has already given you specific instructions.
When can babies have Tylenol?
Acetaminophen should not be given to children under two years of age without guidance from their clinician. From age 2, dose by current weight using the table above.
How often can I give my baby Tylenol?
Only after your child’s clinician has told you to use it and provided the dose. Once you have that, give only as needed with at least 4 hours between doses, and no more than 5 doses in 24 hours.
Can I give my child ibuprofen every 4 hours?
No. Give ibuprofen every 6 to 8 hours, no more than 4 doses in 24 hours. Every 4 hours risks exceeding the daily maximum. If you are reaching for a dose that soon, call us.
Can a 4-month-old have ibuprofen?
Not unless your child’s clinician has specifically directed it. Ibuprofen is not used under 6 months.
How often can I give Tylenol to a toddler?
Under age 2, only with clinician guidance and at the dose we give you. From age 2, use the weight table: at least 4 hours between doses, no more than 5 in 24 hours, rechecked at each well visit.
Does every fever need medicine?
No. For older infants and children, medicine is for discomfort rather than the number on the thermometer, and a child who is drinking, playing and comfortable can often be watched. This does not apply to a baby under 12 weeks with a rectal temperature of 100.4°F (38°C) or higher, which requires immediate medical evaluation.
My child is vomiting and won’t drink. Can I give ibuprofen?
Not without speaking to us. Ibuprofen is harder on the kidneys when a child is short of fluid.
When to reach us
For a same-day concern see Sick Visits; for a newborn, Newborn Visits; weights are updated at Well Visits; if you are not yet a patient, Primary Care.
Source of truth: American Academy of Pediatrics acetaminophen and ibuprofen dosing charts, downloaded 2026-08-30. Reviewed annually, and immediately if a product formulation changes or AAP or FDA guidance is updated.
Sources: AAP acetaminophen · AAP ibuprofen · FDA concentration change · Poison Control