Children's Tylenol & Motrin dose by weight.

This tool looks up your child's weight against the same weight-based dosing chart printed on the Children's Tylenol and Children's Motrin bottles, which is itself derived from American Academy of Pediatrics guidance. Acetaminophen is generally dosed at 10–15 mg/kg every 4–6 hours, with a maximum of 75 mg/kg per day and no more than 5 doses in 24 hours. Ibuprofen is generally dosed at 5–10 mg/kg every 6–8 hours and is not recommended for infants under 6 months of age. Dosing is done by weight, not age, because the label's chart is built around how much drug is in the body relative to body mass — not how many months old a child is.

Once you enter a weight, the result shows both a milliliter amount and a milligram amount. The mL number is what you actually measure and give — always with the dosing syringe that came with the bottle, not a kitchen spoon, since spoons vary in size. The mg number lets you double-check against the bottle's own printed chart. Note that acetaminophen and ibuprofen products aren't interchangeable by volume: Children's Tylenol Oral Suspension is 160 mg per 5 mL, while Children's Motrin Oral Suspension is 100 mg per 5 mL, so the same weight can call for a different number of milliliters depending on which drug you've selected.

• This is a reference tool, not medical advice — always confirm the dose with your pediatrician or pharmacist.
• Never exceed the maximum daily dose printed on the label.
• Don't give ibuprofen to a baby under 6 months old; call your pediatrician and consider acetaminophen instead.
• If you've already given another product containing the same drug (some combination cold-and-flu medicines do), don't redose — check with your pharmacist first.
• For a suspected overdose or wrong dose, call Poison Control at 1-800-222-1222 (US) or local emergency services.

What this calculator can't know: your child's specific medical history, other medications or allergies, how accurate their weight is if it's been a while since the last weigh-in, and whether the symptom you're treating needs medication at all. Fever, in particular, often doesn't need to be treated — AAP guidance is to treat for comfort, not for the number on the thermometer.

Sources: HealthyChildren.org acetaminophen and ibuprofen dosage tables (American Academy of Pediatrics); FDA OTC Drug Facts label, Children's Tylenol & Children's Motrin Oral Suspension; Sullivan & Farrar, 2011, Pediatrics, "Fever and Antipyretic Use in Children."

Before using this tool:

• This is a reference, not medical advice.
• Always confirm with your pediatrician.
• Never exceed the maximum daily dose.
• Do not give ibuprofen to babies under 6 months.
• If you've already given another product containing the same drug (some cold + flu meds do), do not redose.