Pediatric Dosage Calculator

Many children’s medicines are dosed by weight: dose (mg) = mg/kg × weight (kg). A 20 kg child prescribed 15 mg/kg gets 300 mg; at a concentration of 32 mg/mL that is 9.4 mL.

Step by step

1. Convert weight to kg: lb ÷ 2.2046.
2. Dose = mg/kg × kg. Never exceed the maximum single or daily dose on the label or prescription.
3. Volume (mL) = dose (mg) ÷ concentration (mg/mL).

Safety checks

• Use the syringe or cup that comes with the medicine.
• Check the concentration: infant and children’s products can differ.
• Do not give two products with the same active ingredient.

Why weight, not age?

Children of the same age can differ widely in weight, and weight better reflects how the body handles many medicines.

Pediatric Dosage Calculator quiz: 10 questions

Test yourself with 10 multiple-choice questions. Choose an answer and press Submit to see if you are right and why. Your score appears at the end.

Frequently asked questions

How do I calculate a child's dose?

Multiply the prescribed mg/kg by the weight in kg, cap at the maximum, then divide by the concentration for mL.

Is this medical advice?

No. Always follow the prescription and product label.

What if my child's weight is between lines on the label?

Ask a pharmacist; weight-based calculation is usually more precise.

Where are Tylenol and Motrin doses?

See our Tylenol and Motrin dosage by weight calculators.

Can I use pounds?

Yes; the calculator converts.

Sources

• FDA: Use caution when giving cough and cold products to kids / measuring liquid medicine

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