Azithromycin Pediatric Dose Calculator
Weight-based azithromycin dosing for children — 10 mg/kg/dose · once daily · max 500 mg/dose. Enter age and weight for the dose in mg and syrup mL, tablets or injection volume.
Pediatric dosing
Respiratory / ENT infection (3-day course)
Atypical pneumonia (5-day course)
Enteric fever (typhoid), uncomplicated
Pertussis (treatment or post-exposure prophylaxis)
Severe pneumonia — IV (hospital) Hospital
Azithromycin dose chart by age and weight
Respiratory / ENT infection (3-day course). Weights are WHO/IAP reference medians for age — always dose on the measured weight.
| Age | Weight | Dose (mg) | Suspension 100 mg/5 mL | Suspension 200 mg/5 mL | Frequency |
|---|---|---|---|---|---|
| 15 days | 3.8 kg | Below minimum age | |||
| 1 month | 4.3 kg | Below minimum age | |||
| 3 months | 6.1 kg | Below minimum age | |||
| 6 months | 7.6 kg | 76 mg | 3.8 mL | 1.9 mL | Once daily |
| 9 months | 8.6 kg | 86 mg | 4.3 mL | 2.2 mL | Once daily |
| 1 year | 9.3 kg | 93 mg | 4.7 mL | 2.3 mL | Once daily |
| 18 months | 10.6 kg | 106 mg | 5.3 mL | 2.7 mL | Once daily |
| 2 years | 11.8 kg | 118 mg | 5.9 mL | 3 mL | Once daily |
| 3 years | 14.1 kg | 141 mg | 7.1 mL | 3.5 mL | Once daily |
| 4 years | 16.2 kg | 162 mg | 8.1 mL | 4.1 mL | Once daily |
| 5 years | 17.5 kg | 175 mg | 8.8 mL | 4.4 mL | Once daily |
| 6 years | 19 kg | 190 mg | 9.5 mL | 4.8 mL | Once daily |
| 8 years | 24.4 kg | 244 mg | 12 mL | 6.1 mL | Once daily |
| 10 years | 31.1 kg | 311 mg | 15.5 mL | 7.8 mL | Once daily |
| 12 years | 39.4 kg | 394 mg | 19.5 mL | 9.9 mL | Once daily |
Strengths in the calculator
- Suspension 100 mg/5 mL (Oral)
- Suspension 200 mg/5 mL (Oral)
- Tablet 250 mg (Oral — do not split)
- Tablet 500 mg (Oral — do not split)
- 500 mg vial + 4.8 mL water for injection (100 mg/mL) — dilute to 1–2 mg/mL (Intravenous)
Different strength on your bottle? Use “Different strength on the bottle?” under the result.
Safety
Contraindications and cautions
- Known QT prolongation or concurrent QT-prolonging drugs.
Pregnancy and breastfeeding
Legacy FDA category B. Used in pregnancy when a macrolide is needed; confirm against local obstetric guidance.
Compatible with breastfeeding; monitor the infant for diarrhoea.
Clinical notes
Can be taken with or without food. Macrolide resistance is common — reserve for indications where it is preferred.
Adult and adolescent (≥40 kg) dose
500 mg — Once daily for 3 days (max 500 mg per dose).
Alternative 5-day course: 500 mg on day 1, then 250 mg daily. Typhoid: 1 g once daily for 7 days.
Other names and brands
Also known as Azithro.
- India: Azithral, Azee
- USA: Zithromax
- UK: Zithromax
Brand examples only — products and strengths vary by country. Always check the label.
Frequently asked questions
What is the azithromycin dose for children?
Respiratory / ENT infection (3-day course): 10 mg/kg/dose · once daily · max 500 mg/dose. Usual duration: 3 days. Always use the child's measured weight and check the strength on the bottle.
How many mL of suspension 100 mg/5 mL for an 11.8 kg child?
For respiratory / ENT infection (3-day course), an 11.8 kg child (about 2 years) needs 118 mg per dose — 5.9 mL of Suspension 100 mg/5 mL, once daily. Recalculate with the child's actual weight.
From what age can azithromycin be given?
Age range in PediaRx: Pertussis: from birth · other uses: ≥6 months – adult. Each indication can have its own age and weight limits, shown with its regimen.
Is azithromycin safe in pregnancy?
Legacy FDA category B. Used in pregnancy when a macrolide is needed; confirm against local obstetric guidance.
Sources and editorial process
- BNF for Children — Azithromycin — NICE / BMJ Group / Royal Pharmaceutical Society
- Management of community-acquired pneumonia in infants and children older than 3 months (Bradley et al., Clin Infect Dis 2011) — PIDS / IDSA
- Recommended antimicrobial agents for the treatment and postexposure prophylaxis of pertussis (MMWR 2005;54(RR-14)) — U.S. Centers for Disease Control and Prevention
- CDC Yellow Book — Typhoid & paratyphoid fever — U.S. Centers for Disease Control and Prevention
Dosing data last updated 2026-09-27. PediaRx is built and maintained by Dr. Shounak Pal, MBBS (Medical Officer, Government of West Bengal, India — founder and developer of PediaRx). Every regimen is encoded with explicit units, maximum doses and age/weight limits and is checked by automated tests before publication. Report an error: hello@pediarx.com.
Related calculators
Clinical disclaimer: reference tool for qualified health professionals. Verify every dose against current guidance and the product label before prescribing.
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