Pediatric Dose by Weight Calculator
Convert a weight-based pediatric dose (mg/kg) into the total mg for a given patient. Optionally cap the result at an adult maximum and divide the total across the day's administration schedule. The tool flags neonatal weights (<3 kg) and adult-sized pediatric weights (>50 kg) so the clinician verifies the appropriate reference before administering.
Enter values and press Calculate to see the result.
Formula
Total dose (mg) = mg/kg x weight (kg)
If total > adult max (mg), total = adult max.
Per-dose (mg) = total / doses per day.
Clinical notes
- Always verify the mg/kg range, interval, indication, and route against Lexicomp Pediatric & Neonatal, the Harriet Lane Handbook, or an institution-approved reference before administering.
- Neonatal dosing differs substantially from infant/child dosing for many drugs (e.g., gentamicin, ampicillin, acyclovir). This tool warns for weight <3 kg but does not substitute for a neonatal-specific reference.
- Many pediatric protocols transition to adult dosing at or above 40-50 kg — confirm which reference applies.
- This is a general math helper. It does not carry a drug formulary and will not warn on drug-specific maximums beyond the optional adult cap you enter.
Reference: Lexicomp Pediatric & Neonatal Dosing Handbook; The Harriet Lane Handbook (Johns Hopkins Hospital).
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