Pediatric Dose mg/kg - Free Calculator | Federico Calò
Calculate pediatric dose mg/kg for paracetamol, ibuprofen, amoxicillin, and azithromycin with max cap required for each drug. Deterministic based on Taketomo formulary. Calculations in browser - no data sent to server.
Pediatric dosing is based on the mg/kg principle: the medication is administered according to the child's weight, as pharmacokinetics (absorption, distribution, metabolism, excretion) differ significantly from adults until 12-14 years. An insufficient dose is ineffective; an excessive dose risks overdose, with potentially severe consequences - particularly for paracetamol (liver toxicity) and ibuprofen (kidney toxicity).
This tool implements a carefully curated subset of 4 common OTC/prescription drugs: paracetamol (analgesic/antipyretic), ibuprofen (NSAID - contraindicated under 6 kg), amoxicillin (semi-synthetic penicillin, two regimens: standard and high dose for resistance), azithromycin (macrolide - pharyngitis and community-acquired pneumonia CAP). For each drug, the maximum single dose (cap) from the formulary is always displayed - an absolute safety value that the calculator never exceeds regardless of weight.
The dosing values come from: Taketomo CK, Hodding JH, Kraus DM. Pediatric & Neonatal Dosage Handbook (Wolters Kluwer) [ASSUMED - standard international source; always verify against the updated formulary before clinical use]. For drugs not listed, consult the pediatrician or reference pharmacist.
Source form: Taketomo CK, Hodding JH, Kraus DM. Pediatric & Neonatal Dosage Handbook. Wolters Kluwer. Regulatory source IT: AIFA (Italian Medicines Agency).
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Calculation examples (form)
Paracetamol - child 15 kg
- Range: 150-225 mg/dose
- Recommended dose (midpoint): ~188 mg
- Max single dose cap: 1000 mg (not reached)
- Daily max dose: 75 mg/kg/day × 15 = 1125 mg/day (limit: 4000 mg/day)
Ibuprofen - max applied (60 kg)
- Range: 5–10 mg/kg/dose × 60 kg = 150–300 mg/dose (uncapped)
- Midpoint uncapped: 450 mg
- Max dose: 400 mg - the cap is applied: dose = 400 mg
- This is the calculator security golden test (T-52-29-R)
[Values ASSUMED from Taketomo form knowledge - verify against primary source before clinical use.]
Glossary
- Milligrams per kilogram
- Milligrams per kilogram of body weight. Standard unit for pediatric dosing that normalizes the dose to the patient's weight, compensating for age and body mass differences.
- Maximum single dose (cap)
- Absolute limit for single administration defined by the form (Taketomo). It ensures that heavier children do not receive doses higher than those validated for adults, preventing the risk of overdose.
- Newborn (weight < 3 kg)
- Newborns (first 4 weeks of life, usually weight < 3 kg) require specialist dosages due to organ immaturity (kidney, liver). The calculator provides an explicit warning and recommends consulting a neonatologist/pediatrician.
- Ideal weight (IBW)
- Ideal Body Weight - ideal body weight based on height and age, used as a calculation basis for lipophilic drugs in obese children (BMI >97th percentile) to avoid excessive dosing. The calculator defaults to real weight with an explanation of IBW.
Frequently Asked Questions
How is the pediatric dose mg/kg calculated?
The dosage is calculated by multiplying the therapeutic range in mg/kg (specific to the drug and indication) by the child's weight in kg. The recommended value is the midpoint of the range, but it is capped at the maximum single dose from the formulary (Taketomo Pediatric & Neonatal Dosage Handbook). The daily maximum dose is calculated separately and includes the absolute maximum in mg/day.
Why is the single maximum dose shown (max)?
The maximum single dose (cap) is an absolute safety limit of the form: even for heavier children, it must never be exceeded. The tool automatically applies this cap to each calculation and always displays it to prevent the risk of pediatric overdose (maximum safety principle YMYL).
Why is ibuprofen contraindicated under 6 kg?
Ibuprofen is not approved for newborns and small infants (generally < 6 months / < 6 kg) due to the risk of nephrotoxicity associated with reduced neonatal kidney function. For children under this weight threshold, acetaminophen is the preferred analgesic/antipyretic under pediatric indication.
Does this calculator replace the pediatrician's prescription?
Not intended as medical advice. Dosage for children varies based on age, clinical indication, available formulation, co-morbidities, and concurrent medications. Always verify with a pediatrician or pharmacist before administering any medication to a child.
What does [ASSUMED] mean in sources?
The dosage values come from the Taketomo Formulario (Pediatric & Neonatal Dosage Handbook, Wolters Kluwer), which is the international reference for pediatric dosing. The provenance indicates that the values must be verified against the primary source before clinical use - this tool is for educational/informational purposes only, not for clinical operation.
Are data being sent to servers?
No calculations occur on remote servers or with external AI/3rd party. No patient data, medication, or weights are sent to external servers. The tool does not store or process personal data.
How is it used?
- Enter the baby's weight
Enter the current weight of the child in kilograms (e.g., 15 kg). For obese children (BMI >97th percentile), use the ideal weight (IBW) - the calculator defaults to actual weight with a note.
- Select the medication
Choose the medicine from the curated list (paracetamol, ibuprofen, amoxicillin, azithromycin). For other medicines not listed, consult a pediatrician or pharmacist.
- Select indication (if necessary)
For amoxicillin and azithromycin, select the clinical indication (e.g., standard dose vs high dose for amoxicillin, pharyngitis vs pneumonia for azithromycin). The dosage varies significantly.
- Check the result and verify the caps
The calculator shows the recommended single dose (always within the tablet's max limit) and daily maximum dose. Check WITH A DOCTOR OR PHARMACIST BEFORE USE.
Do you need a custom analysis?
This tool is free and informative. For in-depth analysis with AI on-prem - private data, zero cloud - contact Federico.