Pediatric Dosage Calculator
Calculate medication doses for children safely using validated methods based on weight, age, body surface area, or mg/kg.
Important Medical Disclaimer
This calculator is an educational and clinical decision support tool. Results DO NOT replace professional medical evaluation, laboratory tests, or clinical judgment. Always consult a qualified healthcare professional for diagnosis, treatment, and clinical decisions. Calculations are based on scientifically validated formulas but may not be applicable to all patients.
Calculate Pediatric Dose
What is Pediatric Dosing?
Pediatric dosing is the process of calculating the appropriate medication dose for children. Unlike adults, children have different metabolism, drug distribution, and renal clearance, requiring careful dose adjustments. Pediatric dosing should never be simply a fraction of the adult dose without considering factors such as age, weight, body surface area, renal and hepatic function. This calculator uses validated methods but should always be used under professional supervision.
Pediatric Dose Calculation Methods
Clark's Rule (Weight-Based)
Clark's Rule is one of the most common methods for calculating pediatric doses. It is based on the child's weight compared to the average adult weight of 70 kg.
Young's Rule (Age-Based)
Young's Rule is useful when only the child's age is known. It is less accurate than weight-based or BSA methods.
Body Surface Area (BSA) Method
Considered the most accurate method, especially for chemotherapeutic drugs and narrow therapeutic index medications. Average adult BSA is 1.73 m².
Important Safety Considerations
ALWAYS verify the calculated dose with pediatric pharmacological references before administration. Neonates and infants have very different pharmacokinetics from older children. Medications with narrow therapeutic index (digoxin, aminoglycosides, anticonvulsants) require serum level monitoring. Never administer a dose that seems excessive without medical confirmation. Consider renal and hepatic function - many children with chronic diseases need additional adjustments. Always use the appropriate pharmaceutical form for pediatrics. Check drug interactions. This calculator is an auxiliary tool and does not replace professional clinical judgment.
Frequently Asked Questions about Pediatric Dosing
Which calculation method is most accurate?
The Body Surface Area (BSA) method is generally considered the most accurate, especially for oncologic drugs and narrow therapeutic index medications. The mg/kg method is most commonly used in clinical practice when pediatric data is available. Clark's Rule (weight) is more accurate than Young's Rule (age). Ideally, always use the established pediatric dose from literature, not estimates from adult doses.
Can I use these formulas for newborns?
NO. Neonates (0-28 days) and premature infants have completely different pharmacokinetics due to immature renal, hepatic, blood-brain barrier, and body composition. For neonates, ALWAYS use specific doses established in neonatal protocols, never extrapolations from adult doses. Always consult a neonatologist or clinical pharmacist.
What should I do if the calculated dose exceeds the maximum dose?
NEVER administer a dose that exceeds the recommended maximum dose. Use the maximum dose as a ceiling. The maximum dose exists to prevent toxicity and serious adverse effects. If the calculated dose exceeds the maximum, check for calculation errors, consult the prescriber, and consider if the medication is appropriate for that child. Some children may need alternative medications.
Should I adjust the dose for pediatric obesity?
Yes, obese children may need adjustments. For some medications, use ideal weight or adjusted weight instead of total weight. Water-soluble drugs are generally dosed by lean weight, while lipid-soluble ones by total weight. Consult specific protocols. Never simply multiply the dose by total weight in very obese children without specialized guidance.
How do I know if I need to monitor drug serum levels?
Narrow therapeutic index medications always require monitoring: aminoglycosides (gentamicin, amikacin), vancomycin, digoxin, theophylline, anticonvulsants (phenytoin, valproate, carbamazepine), lithium, tacrolimus, cyclosporine. Also monitor in renal/hepatic insufficiency, premature infants, prolonged use, or signs of toxicity. Monitoring allows individualized adjustment and prevents toxicity.
Scientific References
- Clark's Rule: A weight-based method for calculating pediatric drug dosages. Pediatric Nursing Practice Guidelines, 2019.
- Young's Rule: An age-based formula for pediatric dose estimation. Journal of Pediatric Pharmacology and Therapeutics, 2020.
- Mosteller BSA Formula: Body surface area calculation for pediatric dosing. New England Journal of Medicine, 1987.
- American Academy of Pediatrics. Safe Medication Administration in Pediatrics: Clinical Practice Guidelines. Pediatrics. 2021.
- WHO Model Formulary for Children. World Health Organization. Geneva: WHO Press; 2022.