Pediatric Dose Calculator
Calculate pediatric doses by weight or age using Clark's Rule and Young's Rule.
Enter adult dose and child data for safe pediatric medication dosing.
Your data stays in your browser. We do not store, collect, or transmit any information you enter.
Pediatric Dose
How Pediatric Dosing Works
Children are not small adults. Their liver enzymes, kidney clearance rates, and body composition differ dramatically from adults — especially in infants under 12 months. Most over-the-counter medications dose by weight, not age.
Standard weight-based formula:
Dose (mg) = Weight (kg) × Dose per kg (mg/kg)
Then convert to volume:
Volume (mL) = Dose (mg) ÷ Concentration (mg/mL)
Worked example — Children’s ibuprofen:
- Child weight: 22 lb = 10 kg
- Standard ibuprofen dose: 10 mg/kg
- Required dose: 10 × 10 = 100 mg
- Children’s ibuprofen suspension: 100 mg per 5 mL
- Volume to give: 100 ÷ 20 = 5 mL
Common pediatric doses (verify with your pharmacist):
- Acetaminophen (Tylenol): 10–15 mg/kg every 4–6 hours, max 5 doses per 24h
- Ibuprofen (Advil/Motrin): 5–10 mg/kg every 6–8 hours (not for infants under 6 months)
- Amoxicillin: 25–45 mg/kg/day divided every 8–12 hours (prescription)
Weight conversion reminder:
kg = lb ÷ 2.2
A 33 lb child weighs exactly 15 kg.
Critical safety rules:
- Always use the oral syringe included with the medication — kitchen spoons are inaccurate
- Never dose by age alone — a small 4-year-old and a large 4-year-old need different doses
- Double-check concentration — infant drops are often more concentrated than children’s liquid
- Do not give aspirin to children under 16 (risk of Reye’s syndrome)
- When in doubt, call your pediatrician or pharmacist before dosing