Dosage Calculator

Enter your patient's weight, the medication dose (in mg/kg), and the drug concentration to calculate the exact volume to administer. The Dosage Calculator also shows you the total dose in mg and a quick sanity-check of your inputs — helpful for pediatric dosing, nursing calculations, and clinical reference.

Disclaimer: This tool is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any health-related decisions.

kg

Enter the patient's weight in kilograms.

mg/kg

The prescribed dose per kilogram of body weight.

mg/mL

The concentration of the drug solution (mg per mL).

mg

Optional cap on the total dose. Leave at 0 to ignore.

Results

Volume to Administer

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Total Dose

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Weight Used

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Dose Capped?

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Frequently Asked Questions

What is a dosage calculator used for?

A dosage calculator helps healthcare professionals determine the correct amount of medication to administer based on a patient's weight and the drug's prescribed dose per kilogram. It reduces manual calculation errors and is especially important in pediatric care where weight-based dosing is critical.

How is the volume to administer calculated?

The volume is calculated in two steps: first, multiply the patient's weight (in kg) by the dose in mg/kg to get the total dose in mg. Then divide that total dose by the drug concentration (mg/mL) to get the volume in mL. Formula: Volume (mL) = (Weight × Dose per kg) ÷ Concentration.

What does the 'Maximum Dose' field do?

The maximum dose field acts as a safety cap. If the calculated dose based on weight exceeds the maximum, the calculator uses the maximum dose instead. This is common with drugs like Acetaminophen or Ibuprofen where adult dosing limits apply even for heavier children or adolescents.

Can I enter weight in pounds instead of kilograms?

Yes. Select 'Pounds (lb)' from the weight unit dropdown and the calculator automatically converts your entry to kilograms before computing the dose. The weight used in the calculation (in kg) is displayed in the results.

Is this calculator suitable for pediatric dosing?

Yes, this calculator is well-suited for pediatric weight-based dosing. However, all calculated doses should be verified by a qualified healthcare professional before administration. The results here are for reference only and do not replace clinical judgment.

What is mg/kg and why is it used for dosing?

mg/kg stands for milligrams of drug per kilogram of body weight. This method ensures that each patient receives a dose proportional to their size, which is especially important for children whose drug metabolism and body composition differ significantly from adults.

What if I don't know the drug concentration?

The drug concentration (mg/mL) is typically listed on the medication label or package insert. Common examples include Acetaminophen liquid at 32 mg/mL or Ibuprofen suspension at 20 mg/mL. Always verify the concentration before calculating a dose.

Are these calculations guaranteed to be accurate?

This tool provides calculations based on the values you enter, but all results must be verified by a licensed healthcare professional before use. Neither this calculator nor its authors are liable for clinical decisions made based on its output. Always double-check against official prescribing guidelines.