Drug Calculator

This weight-based drug dose calculator computes the total dose required from a patient's weight and a prescribed mg/kg dose, and the volume to administer if a drug concentration is given. This calculator is for educational/informational purposes only and is not a substitute for professional medical judgment.


How to Use the Drug Calculator

  1. Enter the patient's weight in kilograms.
  2. Enter the prescribed dose in milligrams per kilogram (mg/kg).
  3. Optionally, enter the drug's concentration in milligrams per milliliter (mg/mL) to also get the volume to administer.
  4. Click "Calculate" to see the total dose (and volume, if provided).

Frequently Asked Questions

Total Dose (mg) = Patient Weight (kg) x Prescribed Dose (mg/kg). For example, a 70 kg patient at 5 mg/kg needs a 350 mg total dose.

Volume (mL) = Total Dose (mg) / Concentration (mg/mL). This is only shown when you enter a drug concentration.

No. This calculator is for educational and informational purposes only and is not a substitute for professional medical judgment. Always verify dosage calculations with a licensed healthcare provider or pharmacist before clinical use.

Yes, it's completely free, works instantly in your browser, and requires no sign-up.
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