Pediatric Weight-Based Dosing Calculations

Weight-Based Dosing Fundamentals

Pediatric doses are frequently based on the patient's weight in kilograms. The standard conversion is 1 kg = 2.2 lbs. A child weighing 44 lbs equals 20 kg. Always convert pounds to kilograms before calculating the dose.

The dose is expressed as mg/kg/dose or mg/kg/day. For example, if amoxicillin is dosed at 25 mg/kg/day divided into two doses, a 20 kg child would receive 500 mg/day, or 250 mg per dose.

Checking Dose Safety

After calculating a weight-based dose, verify it falls within the safe range listed in the prescribing information. If the calculated dose exceeds the maximum adult dose, the adult dose is used instead. This safety check is a critical pharmacy technician responsibility.

Also consider the concentration of the liquid formulation. If amoxicillin is available as 250 mg/5 mL, a 250 mg dose would be 5 mL.

Practice Resources

Pediatric dosing questions combine unit conversion with dosage calculation. Practice both skills with our PTCB flashcards and mini exam questions.