The fever dosing calculator provides weight-based ibuprofen and acetaminophen doses for children, including the correct volume for common liquid concentrations. Always verify with the package insert and your child's pediatrician.
Child's Information
How to Calculate Pediatric Fever Medication Doses
Pediatric fever dosing should always be based on your child's weight, not age. The standard doses are: acetaminophen 10–15 mg/kg per dose, and ibuprofen 5–10 mg/kg per dose. This calculator uses the middle of the recommended range.
Step 1: Weigh Your Child Accurately
Use a digital scale for the most accurate weight. If measuring in pounds, divide by 2.2 to convert to kg for manual calculations. Always update the dose if your child has gained weight since their last well-child visit.
Step 2: Choose the Right Concentration
Children's acetaminophen and ibuprofen come in multiple concentrations. The most common children's formulations are 160 mg/5mL. Always check your specific bottle — using the wrong concentration can lead to under- or overdosing. Use only the syringe or cup that comes with the medication.
When to Call Your Pediatrician
Always call your pediatrician for: any fever in a baby under 3 months, fever over 104°F (40°C) in any child, fever lasting more than 2–3 days, fever with a rash, stiff neck, difficulty breathing, or a child who appears very ill. Fever itself is not dangerous — it is the body's immune response — but its cause may require evaluation.
FAQ
Is this fever dosing calculator free?
Yes, completely free with no signup required.
Should I dose by weight or age?
Always dose by weight. Package directions that list age-based dosing are only approximations because children of the same age can vary significantly in weight. Dosing by weight is more accurate and safer. Dosing too little is ineffective; dosing too much can cause harm.
Can I give my baby ibuprofen?
No. Ibuprofen (Advil, Motrin) is NOT recommended for infants under 6 months old. For babies under 6 months with fever, use acetaminophen (Tylenol) and always consult your pediatrician.
What is the difference between infant drops and children's liquid?
Infant acetaminophen drops are typically more concentrated (160 mg/5mL is now standard; older formulations were 80mg/0.8mL). Children's liquid is typically 160 mg/5mL. Since the concentrations changed, always read the label on your specific product and use the dosing syringe that comes with it.
How often can I give acetaminophen or ibuprofen?
Acetaminophen: every 4–6 hours as needed, no more than 5 doses in 24 hours. Ibuprofen: every 6–8 hours as needed, no more than 4 doses in 24 hours. Never exceed the maximum daily dose for your child's weight.
Can I alternate acetaminophen and ibuprofen?
Some pediatricians recommend alternating for persistent fever, but this approach increases the risk of dosing errors. The AAP does not have a formal recommendation for alternating. Discuss with your pediatrician before doing this — never give both at the same time.