Infant Tylenol (Acetaminophen) Dosage Calculator
Enter your child's weight to find the safe acetaminophen (Tylenol) dose in both milligrams and millilitres for the standard 160 mg/5 mL liquid. Choose metric or imperial units and a low or standard dose factor. Results update instantly and include the 24-hour maximum, how many doses per day you can give, and the equivalent tablet counts for older children.
How infant Tylenol dosing works
Acetaminophen (the active ingredient in Tylenol, Panadol, and store-brand equivalents) is dosed by body weight, not age. The standard recommendation from the American Academy of Pediatrics is 10 to 15 mg per kilogram of body weight for each dose. Using 15 mg/kg is the most effective for fever and pain relief; 10 mg/kg is a suitable lower starting point for very mild symptoms or when you expect to redose frequently. The dose is given every 4 to 6 hours as needed, and you should never exceed five doses in a 24-hour period. Because infant and children's liquid Tylenol now share the same concentration (160 mg per 5 mL), the same calculation applies to both products. Older products were more concentrated, so always check the bottle label before measuring.
Which formulation to choose
Infants and young children who cannot chew safely should receive the liquid. One teaspoon (5 mL) of the standard liquid contains 160 mg of acetaminophen. Use only the oral syringe or dosing cup that comes with the product; a kitchen spoon can be 20 percent off the target volume. Chewable tablets (80 mg each) are appropriate for children aged 2 and older who can chew without choking. Junior-strength tablets (160 mg each) and adult regular-strength tablets (325 mg) are options for older children and teenagers. Adult tablets are not suitable for infants or toddlers. Suppository forms are available when a child cannot take oral medication but require careful attention to the listed dose on the packaging.
Safety rules and overdose prevention
Acetaminophen overdose is one of the most common causes of acute liver failure in children, almost always from accidental double-dosing. Before giving Tylenol, read the ingredient list on every other medicine in your cabinet because acetaminophen is a hidden ingredient in many combination cold, flu, cough, and allergy products. Never give a second dose sooner than 4 hours after the first. Do not exceed 75 mg/kg/day or five doses in 24 hours. For children under 12 weeks old, acetaminophen should only be given under direct medical supervision. If you suspect a child has swallowed too much acetaminophen, call Poison Control immediately (1-800-222-1222 in the US) even if the child seems fine, because liver damage from overdose may not show symptoms for 24 to 72 hours.
When to call your doctor
This calculator provides a weight-based dose estimate for guidance. Call your pediatrician or seek medical care if your child is under 3 months and has a fever of 100.4 F (38 C) or higher, if fever lasts more than 3 days, if pain or discomfort is not relieved by the correct dose, if your child appears very unwell or difficult to wake, or if you are unsure whether the symptom warrants a fever reducer at all. Dose calculations here are for healthy children at standard body composition; children with kidney disease, liver disease, or who are premature may need a different approach.
Acetaminophen dosage by weight (160 mg / 5 mL liquid)
| Weight (lb) | Weight (kg) | Dose (mg) | Liquid 160 mg/5 mL | Chewable 80 mg | Junior 160 mg |
|---|---|---|---|---|---|
| 6-11 | 2.7-5 | 40 | 1.25 mL | - | - |
| 12-17 | 5.5-7.7 | 80 | 2.5 mL | - | - |
| 18-23 | 8.2-10.4 | 120 | 3.75 mL | 1.5 tabs | - |
| 24-35 | 10.9-15.9 | 160 | 5 mL | 2 tabs | 1 tab |
| 36-47 | 16.3-21.3 | 240 | 7.5 mL | 3 tabs | 1.5 tabs |
| 48-59 | 21.8-26.8 | 320 | 10 mL | 4 tabs | 2 tabs |
| 60-71 | 27.2-32.2 | 400 | 12.5 mL | 5 tabs | 2.5 tabs |
| 72-95 | 32.7-43.1 | 480 | 15 mL | 6 tabs | 3 tabs |
| 96+ | 43.5+ | 640-1000 | 20-31 mL | 8-12 tabs | 4-6 tabs |
Doses use the standard 15 mg/kg factor and are rounded to the nearest 0.25 mL for accurate syringe measurement. Repeat every 4-6 hours; max 5 doses per day.
Frequently asked questions
How do I calculate the correct dose of infant Tylenol?
Multiply your child's weight in kilograms by 15 mg to get the standard single dose in milligrams. If you only know pounds, divide by 2.205 first to get kilograms. Then divide the milligrams by 32 (since the liquid has 160 mg per 5 mL, which equals 32 mg per mL) to find how many millilitres to give. For example, a 20 lb baby is about 9 kg, so the dose is 9 x 15 = 135 mg, and 135 / 32 = about 4.2 mL, rounded to 4.25 mL on the syringe.
What concentration is infant Tylenol?
Since 2011, all infant and children's acetaminophen liquids sold in the US have been standardized to 160 mg per 5 mL. Older products were sold at 80 mg per 0.8 mL (infant drops), which is a different concentration. Always read the label on the bottle you have before giving a dose, especially if it is an older or store-brand product.
How often can I give infant Tylenol?
You may give acetaminophen every 4 to 6 hours as needed, but no more than 5 times in any 24-hour period. Wait at least 4 hours between doses. If your child's fever or discomfort is not controlled after a correctly dosed amount, contact your doctor rather than giving an extra dose.
Can I alternate Tylenol and ibuprofen?
Alternating acetaminophen and ibuprofen (Advil, Motrin) is a practice some doctors recommend for high or persistent fever in children over 6 months. However, it increases the risk of dosing errors because you are tracking two different medications on two different schedules. Only do this under the explicit guidance of your pediatrician, and never give ibuprofen to infants under 6 months old.
What if my child spits out part of the dose?
There is no reliable way to estimate how much was actually swallowed, so it is generally not safe to give a second full dose. Wait the full 4 hours and then give the correct next dose at that time. If you are concerned your child did not get enough relief, contact your pediatrician for guidance.
Is infant Tylenol safe for newborns?
Acetaminophen should not be given to infants under 12 weeks of age without direct guidance from a doctor. One exception recognized by some guidelines is a single dose given after an immunization at 8 weeks, but even then it should only be done if a healthcare provider explicitly recommends it. For newborns, always call your doctor before giving any medication.
What is the maximum daily dose of acetaminophen for children?
The maximum is the lower of 5 doses (at your chosen mg/kg factor) or 75 mg/kg in a 24-hour period, with an absolute ceiling of 5000 mg per day for adults. In practice, for infants and young children the weight-based limit of 75 mg/kg/day is reached first. Never exceed five doses in 24 hours regardless of weight.