A pediatric dosage calculator determines the correct medication dose for a child based on their body weight in kilograms. Weight-based dosing (mg/kg) is the standard method for prescribing medications to children, since adult fixed doses are often too high for smaller bodies. Enter the child's weight and select a medication below to calculate the recommended dose and liquid volume instantly.
Medical Disclaimer
This calculator is for educational and reference purposes only. It is NOT a substitute for professional medical advice. Always consult a licensed physician or pharmacist before administering any medication to a child. Dosing errors can be dangerous.
Dosage Parameters
Check the medication label for mg per mL
Dosing Details
For educational purposes only — always verify pediatric medication doses with a licensed physician or pharmacist before administering. This tool does not account for individual medical conditions, allergies, or drug interactions.
Common Liquid Medication Concentrations
Check the label on your specific product. Concentrations vary by brand and formulation.
| Medication | Infant Drops | Children's Liquid |
|---|---|---|
| Acetaminophen (Tylenol) | 160 mg/5 mL | 160 mg/5 mL |
| Ibuprofen (Advil/Motrin) | 50 mg/1.25 mL | 100 mg/5 mL |
| Amoxicillin | -- | 125 or 250 mg/5 mL |
| Azithromycin | -- | 100 or 200 mg/5 mL |
| Cefalexin | -- | 125 or 250 mg/5 mL |
| Prednisolone | -- | 5 or 15 mg/5 mL |
Always verify the concentration on your specific product label before calculating a dose.
How to Use the Pediatric Dosage Calculator
Calculating the correct medication dose for a child is critical because pediatric patients cannot safely take standard adult doses. The pediatric dosage calculator uses weight-based dosing (mg/kg) to determine the appropriate amount of medication per administration, along with the liquid volume needed based on the formulation's concentration.
Step 1: Enter the Child's Weight
Weigh the child and enter the value in kilograms or pounds. Use the toggle to switch units. If you enter pounds, the calculator automatically converts to kilograms (dividing by 2.205) since all dosing guidelines use metric weight. For infants, use a scale accurate to the nearest 0.1 kg for the most precise dosing.
Step 2: Select the Medication
Choose from common pediatric medications in the dropdown, including acetaminophen, ibuprofen, amoxicillin, azithromycin, cefalexin, and prednisolone. Each medication has pre-loaded dosing parameters based on standard pediatric drug dosing guidelines. For medications not listed, select "Custom Medication" and enter the mg/kg dose and frequency as directed by a healthcare provider.
Step 3: Enter the Liquid Concentration
Check the medication bottle label for the concentration in mg/mL (for example, children's acetaminophen is commonly 160 mg per 5 mL, which equals 32 mg/mL). Enter this value so the calculator can determine the exact volume in milliliters to administer per dose. The reference table below the calculator lists common concentrations.
Step 4: Review the Results
The calculator displays four key values: the dose in milligrams per administration, the volume in milliliters per dose, the total daily dose in mg/kg/day, and the dosing schedule (frequency). If the calculated daily dose exceeds the maximum recommended amount, a red warning appears. Always use a calibrated oral syringe to measure liquid doses precisely.
Understanding mg/kg Dosing
The mg/kg system ensures that each child receives a dose proportional to their body size. A 10 kg toddler and a 30 kg child taking the same medication need different amounts. The mg/kg calculator multiplies the child's weight by the recommended per-kilogram dose to produce the correct amount. Most pediatric references express doses as mg/kg/dose (per single administration) or mg/kg/day (total daily amount divided across multiple doses).
Important Safety Notice
This tool is for educational reference only and must not replace professional medical judgment. Dosing depends on the specific diagnosis, the child's age and organ function, potential drug interactions, and allergies. Never administer medication to a child without first consulting a qualified healthcare provider. When in doubt, contact your pediatrician or pharmacist.
FAQ
Is this pediatric dosage calculator free?
Yes, this calculator is completely free with no limits. You can calculate medication doses as many times as you need. There is no signup required, and all calculations run locally in your browser.
Is my data safe and private?
Yes, all calculations run entirely in your browser using client-side JavaScript. No patient data, weights, or medication information is sent to any server or stored anywhere. Your data stays on your device only.
How does weight-based dosing work?
Weight-based dosing calculates medication amounts using the child's weight in kilograms multiplied by the recommended dose in milligrams per kilogram (mg/kg). For example, if a medication is dosed at 10 mg/kg and the child weighs 20 kg, the dose would be 200 mg. This ensures doses are proportional to the child's size.
What does mg/kg mean?
The notation mg/kg means milligrams of medication per kilogram of body weight. It is the standard way pediatric doses are prescribed, since children vary widely in size. A dose of 15 mg/kg means 15 milligrams of the drug for every kilogram the child weighs.
What common medications does this calculator cover?
This calculator includes dosing for acetaminophen (Tylenol), ibuprofen (Advil/Motrin), amoxicillin (standard and high-dose), azithromycin (Zithromax), cefalexin (Keflex), and prednisolone. You can also enter custom mg/kg doses for any other medication as directed by a healthcare provider.
Is this a substitute for professional medical advice?
No, absolutely not. This calculator is for educational and reference purposes only. Always consult a licensed physician, pharmacist, or other qualified healthcare provider before administering any medication to a child. Dosing decisions must account for the child's medical history, allergies, and other medications.
How should I measure liquid medications?
Always use a calibrated oral syringe or dosing cup marked in milliliters (mL). Never use household spoons, as they vary in size and lead to inaccurate dosing. Draw up the exact volume shown by the calculator using the syringe markings for the most accurate dose.
Does this calculator work for infant dosing?
This calculator computes doses based on weight using standard mg/kg guidelines, which apply to infants as well. However, infant dosing requires extra caution due to immature organ function. Always verify infant doses with a pediatrician or pharmacist before administering any medication.