Free Amoxicillin Pediatric Dosage Calculator

Pediatric Amoxicillin Dosing: A Practical Reference Guide

Determining the correct amoxicillin dose for children is a critical step in treating common bacterial infections while minimizing side effects. This pediatric amoxicillin dosing tool delivers evidence‑based recommendations that account for the child’s weight, age, and clinical indication. It functions as a child amoxicillin calculator that provides both the required milligram amount and the corresponding volume of oral suspension, following guidelines from the World Health Organization (WHO) and the American Academy of Pediatric Dentistry.

The calculator covers a wide range of bacterial illnesses, including otitis media, pharyngitis, urinary tract infections, streptococcal pharyngitis (Strep A), and infective endocarditis prophylaxis. The amoxicillin dosage by weight principle forms the foundation of all recommendations, ensuring that each child receives an amount proportional to their body size.

How the Amoxicillin Suspension Dosage Tool Works

To generate a personalized amoxicillin suspension dosage, the user provides:

• Age (1 month to 18 years)
• Weight (in kilograms, pounds, or other units)
• Suspension strength (125 mg/5 mL, 250 mg/5 mL, 200 mg/5 mL, or 400 mg/5 mL)
• Indication (general infection, Strep A, or endocarditis prophylaxis)
• Route of administration (oral or intravenous)

Based on these inputs, the tool calculates the per‑dose and daily total, and it also displays the exact volume of suspension needed when the oral route is selected.

Step‑by‑Step Dosage Calculation

The core formula for any weight‑based dose is:

$$\text{Dose (mg)} = \text{Weight (kg)} \times \text{Recommended mg/kg per dose}$$

When the recommended amount is expressed as a daily total divided into multiple administrations, the per‑dose amount becomes:

$$\text{Dose per administration (mg)} = \frac{\text{Weight (kg)} \times \text{Daily mg/kg}}{\text{Number of daily doses}}$$

To convert the calculated milligram dose into milliliters of suspension:

1. Compute the concentration per mL:

   $$\text{Strength per mL} = \frac{\text{Total amoxicillin (mg)}}{\text{Total volume (mL)}}$$

   For instance, a 400 mg/5 mL suspension yields $\frac{400}{5} = 80\ \text{mg/mL}$.

2. Divide the required mg dose by this concentration:

   $$\text{Volume (mL)} = \frac{\text{Dose (mg)}}{\text{Strength per mL}}$$

Example:
A 10 kg child with a routine infection is prescribed 15 mg/kg/dose. The computed dose is $15 \times 10 = 150\ \text{mg}$. Using a 125 mg/5 mL suspension (25 mg/mL), the needed volume is $150 \div 25 = 6\ \text{mL}$.

Dosing Regimens by Indication

General Bacterial Infections – Oral Route

Parameter	Value
Dose range	15–30 mg/kg/dose
Maximum per dose	500 mg
Maximum daily dose	4 g
Frequency	Every 8 hours (3 doses/day)

General Bacterial Infections – Intravenous Route

Parameter	Value
Dose range	30–60 mg/kg/dose
Maximum per dose	1 g
Maximum daily dose	4 g
Frequency	Every 8 hours (3 doses/day)

Strep A Pharyngitis – Oral Route

Weight Group	Dose
<15 kg (<33 lb)	50 mg/kg/dose
15–29 kg (33–64 lb)	750 mg/dose
≥30 kg (≥66 lb)	1000 mg/dose

Note: For children ≥15 kg the dose is fixed per administration, not weight‑based. This regimen is taken once daily for 10 consecutive days.

Infective Endocarditis Prophylaxis – Oral or IV

• Dose: 50 mg/kg/dose (single administration; maximum 2 g)
• Timing: Given 30–60 minutes before the procedure

Important Safety Considerations

This tool is designed for informational purposes and does not replace professional medical advice. Dosing may require adjustment based on renal function, allergy history, and local antimicrobial resistance patterns. Always consult a healthcare provider before starting or changing therapy.

Amoxicillin is a broad‑spectrum penicillin‑type antibiotic that kills susceptible bacteria or stops their growth. It is frequently combined with clavulanic acid, a β‑lactamase inhibitor that extends its activity against resistant organisms. Oral amoxicillin suspension is the most common pediatric formulation, and its strength (mg per mL) must be verified on the product label before measuring a dose.

For infants older than one month, the weight‑based dosing rules are the same as for older children. The calculator should not be used for neonates under one month of age because their renal and hepatic function alters drug clearance. Overdose symptoms, though uncommon, may include nausea, vomiting, diarrhea, abdominal pain, and in severe cases, convulsions or renal failure. Supportive care and hemodialysis are the mainstays of overdose management.

The maximum daily dose for oral amoxicillin is 4 g; individual oral doses should not exceed 500 mg. For intravenous administration, the per‑dose limit is 1 g. During endocarditis prophylaxis, a single oral or IV dose of up to 2 g is used.

By integrating weight, age, indication, and suspension strength, this free children’s amoxicillin dose tool helps caregivers and clinicians quickly verify that a prescribed regimen falls within the recognized safe and effective range.