What is the standard amoxicillin dose for ear infections?

Standard acute otitis media dosing is often 40–45 mg/kg/day divided into 2 or 3 doses, while high-dose regimens of 80–90 mg/kg/day are used when resistant organisms are a concern. The prescribed regimen should follow the child's diagnosis, age, and local resistance patterns.

When should high-dose amoxicillin be used?

High-dose amoxicillin is commonly chosen when penicillin-resistant Streptococcus pneumoniae is more likely, such as with younger children, recent antibiotic exposure, daycare attendance, or treatment failure on a lower dose. The prescribing clinician determines whether that higher target is appropriate.

How do I measure the suspension accurately?

Use the oral dosing syringe provided with the medication. Kitchen teaspoons are inaccurate and should not be used for pediatric medications, because they vary too much in size.

Does amoxicillin need to be refrigerated?

Yes. Once reconstituted, amoxicillin suspension should be refrigerated and used within 14 days. Shake well before each dose.

What if my child vomits after taking amoxicillin?

If vomiting occurs within 30 minutes, redose. If more than 30 minutes have passed, the dose was likely absorbed and should not be repeated.

Can amoxicillin be given with food?

Yes. Amoxicillin can be taken with or without food. Giving it with food may reduce stomach upset in sensitive children.

Amoxicillin Pediatric Dosage Calculator

Calculate pediatric amoxicillin doses by weight, indication, and formulation. Includes suspension volume, dosing schedules, and indication-specific reference tables.

⚠️ Medical Disclaimer: Pediatric dosing must be confirmed by a healthcare provider. This calculator provides general guidance based on standard references. Individual patient factors (allergies, renal function, drug interactions) must be assessed.

Child Weight

Child Age

years

Formulation

Indication

Dose Intensity

Duration of Treatment

days

Per Dose Volume

4.0 mL

(0.8 tsp) — Every 8 hours (TID)

Dose per kg/day

40 mg/kg/day

Every 8 hours (TID)

Calculated Daily Dose

600 mg/day

Within pediatric range

Per Dose

200 mg

4.0 mL of 250 mg/5 mL

mL per Dose

4.0 mL

~0.8 teaspoons

Total mL for Course

120 mL

10 days × 3 doses/day

Bottles Needed

Standard 100 mL bottles

Dosing Schedule

Time	Dose (mg)	Volume (mL)	Notes
8:00 AM	200 mg	4.0 mL	Can give with food
2:00 PM	200 mg	4.0 mL	Space doses evenly
8:00 PM	200 mg	4.0 mL	Space doses evenly

Dosing by Indication

Indication	Standard Dose	High Dose	Duration
Acute Otitis Media	40–45 mg/kg/day TID	80–90 mg/kg/day BID	10 days (<2y), 5–7 days (≥2y)
Pharyngitis/Tonsillitis	25 mg/kg/day BID	50 mg/kg/day BID	10 days
Sinusitis	45 mg/kg/day TID	90 mg/kg/day BID	10–14 days
Pneumonia (CAP)	45 mg/kg/day TID	90 mg/kg/day TID	7–10 days
UTI	25 mg/kg/day TID	40 mg/kg/day TID	7–14 days
Skin Infection	25 mg/kg/day TID	40 mg/kg/day TID	7–10 days

Formulation	Concentration	Typical Use
125 mg/5 mL	Lower concentration	Infants, small children
200 mg/5 mL	Medium concentration	BID dosing formulation
250 mg/5 mL	Standard concentration	Most commonly prescribed
400 mg/5 mL	High concentration	Older/heavier children, fewer mL

Planning notes, formulas, and examples

About the Amoxicillin Pediatric Dosage Calculator

The Amoxicillin Pediatric Dosage Calculator provides weight-based dosing for one of the most commonly prescribed antibiotics in children. Amoxicillin, a broad-spectrum penicillin, is used to treat ear infections, strep throat, sinusitis, pneumonia, urinary tract infections, and skin infections in pediatric patients. The goal is to translate the prescribed mg/kg/day range into a practical dose volume without changing the underlying prescription.

Proper dosing in children requires precise weight-based calculations to ensure therapeutic drug levels while minimizing side effects. The standard dosing ranges from 25 mg/kg/day for mild infections up to 90 mg/kg/day for resistant organisms (such as penicillin-resistant Streptococcus pneumoniae in acute otitis media). The calculator converts these mg/kg doses into practical volume measurements (mL and teaspoons) based on the specific suspension concentration dispensed.

This calculator also helps estimate the total medication volume needed for the treatment course, helping parents prepare and pharmacies dispense the correct quantity. While highly useful, dosing should always be confirmed by the prescribing pediatrician or pharmacist.

When This Page Helps

Incorrect antibiotic dosing in children is a common issue — under-dosing contributes to antibiotic resistance, while over-dosing increases side effect risk. Weight-based calculations are essential because children vary enormously in size, and fixed doses appropriate for one child may be dangerous or ineffective for another. This calculator bridges the gap between the physician prescription (mg/kg/day) and the practical measurement parents need (mL of suspension per dose), reducing medication errors.

How to Use the Inputs

Enter the child's weight in kilograms (weigh the child if possible for accurate dosing).
Enter the child's age in years for reference.
Select the suspension formulation dispensed (125, 200, 250, or 400 mg/5 mL).
Choose the clinical indication (ear infection, strep throat, etc.).
Select standard or high-dose intensity based on the physician order.
Enter the prescribed duration of treatment.
Review the per-dose volume, daily schedule, and total course requirements.

Formula used

Daily Dose = Weight (kg) × Dose Rate (mg/kg/day)
Per-Dose Amount = Daily Dose ÷ Number of Doses/Day
Volume per Dose (mL) = (Per-Dose mg ÷ Concentration mg) × 5 mL
Total Course Volume = Volume per Dose × Doses/Day × Treatment Days

Example Calculation

Result: 200 mg per dose (4 mL), three times daily

A 15 kg child with acute otitis media at standard dose (40 mg/kg/day) receives 600 mg/day. Divided into three doses: 200 mg each. Using 250 mg/5 mL suspension, each dose is 4 mL.

Tips & Best Practices

Always weigh the child in kg — do not estimate. Even 1–2 kg differences significantly affect the dose.
Use the oral syringe provided with the suspension, not kitchen spoons.
Complete the full antibiotic course even if symptoms improve — stopping early promotes resistance.
Store reconstituted suspension in the refrigerator; discard after 14 days.
If a dose is missed, give it as soon as remembered unless it is near the next dose time.
Watch for allergic reactions (rash, hives, swelling) — amoxicillin allergy occurs in ~5–10% of patients.

Amoxicillin Resistance Considerations

The rise of penicillin-resistant Streptococcus pneumoniae has shifted treatment paradigms in pediatrics. High-dose amoxicillin (80–90 mg/kg/day) achieves higher middle ear fluid concentrations that can overcome intermediate resistance. Risk factors for resistant organisms include age under 2, daycare attendance, recent antibiotic use (within 90 days), and geographic regions with high resistance rates.

Choosing the Right Suspension Concentration

The 125 mg/5 mL formulation is ideal for infants and small toddlers who need small volumes. The 250 mg/5 mL concentration is the most commonly dispensed for typical pediatric patients. The 400 mg/5 mL concentration is preferred for high-dose regimens in older or heavier children, as it reduces the volume per dose — improving palatability and adherence. Pharmacists may substitute concentrations based on availability.

Duration of Therapy Guidelines

Treatment duration varies by indication: acute otitis media in children under 2 typically requires 10 days, while children over 2 with mild disease may be treated for 5–7 days. Group A strep pharyngitis always requires a full 10-day course to prevent rheumatic fever. Sinusitis treatment ranges from 10–14 days. Shorter courses may be appropriate for uncomplicated UTIs. Always follow the prescriber's recommended duration.

Sources & Methodology

Last updated: March 28, 2026

Methodology

This worksheet turns labeled pediatric mg/kg/day ranges into per-dose volume and course totals using the selected suspension strength and schedule.

Sources

FDA amoxicillin oral suspension labeling (FDA)
Harriet Lane Handbook pediatric dosing references (Elsevier)
MedlinePlus: Amoxicillin (NIH)

Frequently Asked Questions

Standard acute otitis media dosing is often 40–45 mg/kg/day divided into 2 or 3 doses, while high-dose regimens of 80–90 mg/kg/day are used when resistant organisms are a concern. The prescribed regimen should follow the child's diagnosis, age, and local resistance patterns.