Pediatric Fever Management Calculator
Estimates an appropriate acetaminophen or ibuprofen dose for a feverish child based on weight, age, temperature, and symptom severity. Use it to quickly check dosing before reaching for a measuring syringe.
About this calculator
The calculator uses a weight-based approach modified by age and symptom severity. The formula is: Dose (mg) = childWeight × medicationFactor × severityMultiplier × ageFactor + tempBonus, where medicationFactor is 15 mg/kg for acetaminophen and 10 mg/kg for ibuprofen (standard evidence-based starting points); severityMultiplier is 0.8 for mild, 1.0 for moderate, and 1.2 for severe symptoms; ageFactor is 0.5 for children under 2 years and 1.0 for children aged 2 and above; and tempBonus adds 50 mg when temperature exceeds 39 °C. The core mg/kg figures reflect widely used clinical guidelines: acetaminophen 10–15 mg/kg and ibuprofen 5–10 mg/kg per dose every 4–6 and 6–8 hours respectively. Ibuprofen should not be used in children under 6 months.
How to use
A 3-year-old child weighs 14 kg, has a temperature of 39.5 °C, moderate symptoms, and will receive acetaminophen. Dose = 14 × 15 × 1.0 × 1.0 + 50 = 210 + 50 = 260 mg. Enter childWeight = 14, temperature = 39.5, childAge = 3, medication = acetaminophen, symptomSeverity = moderate. The calculator returns 260 mg. A typical children's acetaminophen liquid contains 160 mg per 5 mL, so this would be approximately 8.1 mL. Always re-check against the product label and consult a pharmacist or doctor if unsure.
Frequently asked questions
What is the correct acetaminophen dose per kg for children?
The standard evidence-based dose for acetaminophen (paracetamol) in children is 10–15 mg per kilogram of body weight per dose, given every 4–6 hours as needed, with a maximum of 5 doses in 24 hours. Staying within the 10–15 mg/kg range is important because acetaminophen overdose is the leading cause of acute liver failure in children. Always calculate the dose based on the child's current weight, not their age, and measure liquid doses with the calibrated syringe or cup supplied with the product rather than a household spoon. If a child has liver disease, consult a doctor before giving any acetaminophen.
When should I take a child with a fever to the emergency room?
Seek emergency care immediately if a child under 3 months has any fever above 38 °C, if a child of any age has a fever above 40 °C that does not come down with appropriate medication, or if the child shows signs of serious illness such as difficulty breathing, a stiff neck, a rash that does not blanch under pressure, persistent vomiting, severe headache, or unusual drowsiness. Febrile seizures, while frightening, are common in young children and are not necessarily dangerous on their own, but the child should still be evaluated. A fever that lasts more than 5 days without improvement also warrants a medical review regardless of its height.
Why is ibuprofen not recommended for infants under 6 months old?
Ibuprofen is an NSAID (non-steroidal anti-inflammatory drug) that can affect kidney blood flow and prostaglandin synthesis. In infants under 6 months, the kidneys are still maturing and are particularly vulnerable to these effects, raising the risk of acute kidney injury even at normal doses. There is also limited safety and pharmacokinetic data for this age group, so regulatory agencies including the FDA and EMA have not approved ibuprofen for children under 6 months. Acetaminophen is the recommended analgesic and antipyretic for young infants when given at the correct weight-based dose under medical guidance.