Amoxicillin Pediatric Dosage Calculator
The Amoxicillin Pediatric Dosage Calculator estimates a child's daily and per-dose amoxicillin requirement from body weight. It multiplies weight by the prescribed milligrams per kilogram per day, then divides the daily total by the number of doses. The formula used is: daily dose = weight × mg/kg/day; per dose = daily dose ÷ doses per day.
Rates and fees change frequently. Always confirm the current figures
with the official authority before relying on this result.
Formula
daily dose = weight × mg/kg/day; per dose = daily dose ÷ doses per day
- The Amoxicillin Pediatric Dosage Calculator turns a child's weight into a daily and per-dose amoxicillin amount and updates instantly as you change any value.
- Formula: daily dose = weight × mg/kg/day; per dose = daily dose ÷ doses per day
- Input definitions: • Child Weight: the child's body weight in kilograms • Dose per kg per Day: the prescribed milligrams per kilogram per day (commonly 25–45 mg/kg/day, up to 80–90 for some infections) • Doses per Day: how many times per day the dose is split (usually 2 or 3)
- Enter weight in kilograms and the mg/kg/day your prescriber specified.
- This tool provides an educational estimate only. The correct dose depends on the infection, the child's age and kidney function, and the product concentration — always follow the prescription and product label.
- Practical tip: confirm the per-dose volume (mL) using the suspension strength printed on the bottle, e.g. 250 mg/5 mL.
Example Calculation
Inputs
- Child Weight: 18 kg
- Dose per kg per Day: 45 mg/kg/day
- Doses per Day: 2 /day
For an 18 kg child at 45 mg/kg/day, the daily dose is 18 × 45 = 810 mg. Split into 2 doses, that is 405 mg per administration. Round to the nearest practical volume of the prescribed suspension.
Frequently asked questions
How is a pediatric amoxicillin dose calculated?
Multiply the child's weight in kilograms by the prescribed milligrams per kilogram per day, then divide by the number of doses per day. For example, 18 kg × 45 mg/kg/day ÷ 2 doses = 405 mg per dose.
What mg/kg/day should I use?
Common amoxicillin dosing is 25–45 mg/kg/day for many infections, rising to 80–90 mg/kg/day for conditions such as acute otitis media. Use the value your prescriber specifies.
Why does my doctor's dose differ from this estimate?
Dosing also depends on the infection, the child's age and kidney function, and the available suspension strength. The prescriber's instructions always take precedence.
How do I convert milligrams to millilitres?
Divide the dose in mg by the suspension concentration. With 250 mg/5 mL (50 mg/mL), a 405 mg dose is 405 ÷ 50 ≈ 8.1 mL.
Is this calculator a substitute for medical advice?
No. It is an educational estimate. Confirm every dose with a qualified healthcare professional before giving medication to a child.