Pediatricians do not prescribe amoxicillin by age — they prescribe it by weight. The correct amoxicillin 250 mg tablet dosage for child depends entirely on how much the child weighs and what infection is being treated. For ear infections and strep throat, the standard dose is 25 to 50 mg per kilogram per day, divided into two or three doses. For pneumonia, the higher dose of 80 to 90 mg per kilogram per day is used to overcome resistance in Streptococcus pneumoniae. For severe infections, doses may reach 100 mg per kilogram per day. A 40-pound child weighs about 18 kg, so a strep throat course might be 450 to 900 mg per day depending on the chosen dose. This guide provides accurate pediatric dosing based on FDA labeling and American Academy of Pediatrics guidelines.
Why Weight-Based Dosing Is Required
Children’s bodies distribute and clear antibiotics differently than adults. A dose that provides adequate blood levels in a 60-pound 8-year-old would be excessive for a 20-pound toddler and inadequate for a 120-pound teenager. Weight-based calculation ensures each child gets the concentration needed to effectively clear bacteria without unnecessary exposure.
Amoxicillin is particularly forgiving because its therapeutic window is wide, but underdosing leads to treatment failure and resistance development, while overdosing increases side effects.
Available Pediatric Formulations
Amoxicillin comes in several forms useful for children:
- Oral suspension: 125, 200, 250, and 400 mg per 5 mL — the most common pediatric formulation
- Chewable tablets: 125, 200, 250, and 400 mg
- Capsules: 250 and 500 mg (for older children who can swallow capsules)
- Tablets: 500 and 875 mg (older children and adolescents)
The 250 mg chewable tablet or 250 mg per 5 mL suspension are common choices for children 3 years and older. Younger children usually receive liquid suspension for accurate dosing.
Standard Dosing by Indication
Acute Otitis Media (Ear Infection)
The American Academy of Pediatrics recommends 80 to 90 mg per kilogram per day, divided into two doses, for 10 days in children under 2 years and 5 to 7 days in older children. The higher dose is used because of reduced susceptibility in pneumococcus. Example: a 22-pound (10 kg) child receives 450 mg twice daily for 10 days.
Strep Throat (Streptococcal Pharyngitis)
50 mg per kilogram per day, divided into twice-daily or once-daily dosing, for 10 days. Maximum 1,000 mg per day. Example: a 40-pound (18 kg) child receives 450 mg twice daily or 900 mg once daily for 10 days.
Community-Acquired Pneumonia
90 mg per kilogram per day, divided into three doses, for 5 to 10 days. Maximum 4 grams per day. Example: a 44-pound (20 kg) child receives 600 mg three times daily.
Acute Bacterial Sinusitis
Amoxicillin-clavulanate is now preferred over plain amoxicillin, but when plain amoxicillin is used, the dose is 80 to 90 mg per kilogram per day divided into two doses for 10 to 14 days.
Dental Infections
25 to 50 mg per kilogram per day divided into three doses for 5 to 7 days.
Urinary Tract Infections
Amoxicillin is no longer preferred for pediatric UTIs due to resistance, but when used, the dose is 25 to 50 mg per kilogram per day divided into three doses for 7 to 10 days.
Endocarditis Prophylaxis Before Dental Procedures
50 mg per kilogram (maximum 2 grams) as a single dose 30 to 60 minutes before the procedure.
Weight-Based Dosing Chart
Quick reference for strep throat at 50 mg/kg/day divided twice daily:
- 15 lbs (7 kg): 175 mg twice daily
- 22 lbs (10 kg): 250 mg twice daily
- 33 lbs (15 kg): 375 mg twice daily
- 44 lbs (20 kg): 500 mg twice daily
- 55 lbs (25 kg): 625 mg twice daily
- 66 lbs (30 kg): 750 mg twice daily
- 88 lbs (40 kg) or more: Use adult dosing
For higher-dose indications like otitis media and pneumonia, approximately double these amounts. The American Academy of Pediatrics provides complete dosing tables in its treatment guidelines.
Measuring the Dose Accurately
Always use the oral syringe or dosing cup that came with the bottle. Kitchen teaspoons vary in volume and are a leading cause of pediatric medication errors. For the 250 mg per 5 mL suspension, a 500 mg dose is exactly 10 mL (two teaspoons), not “a couple of spoonfuls.”
Shake the suspension vigorously before each dose. The medication settles and the first and last doses of a bottle contain very different concentrations if not shaken properly. Refrigeration after reconstitution is recommended for most suspensions.
How to Give Amoxicillin to Kids
A few practical tips:
- Food is optional. Amoxicillin can be given with or without food. Food may reduce nausea.
- Mix with a small amount of liquid or soft food if needed. Avoid hot drinks and do not mix into an entire bottle — the child may not finish it and will receive an underdose.
- Complete the full course even if symptoms resolve early. Stopping early leads to relapse and resistance.
- Space doses evenly. For twice-daily dosing, every 12 hours. For three-times-daily, every 8 hours. Consistent timing matters.
- If a dose is missed, give it as soon as you remember unless it is close to the next dose. Never double up.
Common Side Effects
Most children tolerate amoxicillin well. Common side effects include diarrhea (up to 9 percent), nausea, stomach upset, diaper rash from yeast overgrowth, and non-allergic rash. Probiotics may help reduce antibiotic-associated diarrhea, though evidence is mixed.
A rash appearing on day 5 to 10 of treatment is often a delayed maculopapular rash unrelated to true penicillin allergy. It usually does not require stopping the antibiotic, but should be evaluated by a pediatrician. The Mayo Clinic drug reference covers the distinction between true allergic reactions and benign drug rashes.
Allergic Reactions
True IgE-mediated penicillin allergy — hives, facial swelling, wheezing, anaphylaxis — is relatively rare. When it occurs, amoxicillin must be stopped immediately and future exposure avoided. Severe reactions like Stevens-Johnson syndrome, though very rare, require emergency care. Our medical conditions guide covers more on common childhood infections and antibiotic selection.
When to seek emergency care: Call 911 or go to the emergency room if your child develops hives with facial or throat swelling, difficulty breathing, severe vomiting, bloody or severe diarrhea, blistering skin rash, or any sudden severe reaction after a dose.
Frequently Asked Questions
How much amoxicillin should a 5-year-old take?
It depends on the child’s weight and the infection. An average 5-year-old weighing 40 pounds (18 kg) would typically receive about 450 mg twice daily for strep throat (50 mg/kg/day) or about 800 mg twice daily for ear infection (90 mg/kg/day). Always follow the specific prescription.
Is the 250 mg tablet the right size for children?
The 250 mg chewable tablet is appropriate for children whose calculated dose matches 250 mg. For smaller children, liquid suspension allows more precise dosing. For larger children, the 500 mg tablet may be needed. Your pediatrician will calculate the correct strength.
Can I crush the 250 mg amoxicillin tablet?
Regular tablets can be crushed if needed, but chewable tablets are specifically designed to be chewed or crushed easily. Mix crushed medication with a small amount of soft food the child will eat all of.
How long does amoxicillin take to work in kids?
Fever and pain usually improve within 48 to 72 hours for ear infections, strep throat, and pneumonia. If your child is not improving by day 3, contact the pediatrician. Complete the full course even if symptoms resolve early.
The Bottom Line
Pediatric amoxicillin dosing is based on weight: 50 mg/kg/day for strep throat, 80 to 90 mg/kg/day for ear infection and pneumonia, divided into two or three doses. Use the dosing syringe that came with the suspension, shake the bottle before each dose, and complete the full course. For more guidance, see our related coverage of adult amoxicillin dosing, what amoxicillin treats, and ibuprofen dosing for kids.