Dosage calculation by PharmCalculator

Created by Jerry Liu and Shaopan Gao, 

Supervised by Dr. Yue He and Dr. Song Gao

Dosage Calculation Disclaimer: This dosage calculator is provided for educational purposes only and should not replace professional medical advice. The calculated doses are based on simplified assumptions and may not be appropriate for all patients. Always consult with a healthcare professional for individualized treatment recommendations.


Dosage calculation


Estimated Dose Equivalents


Pharmacy Calculation---dilutions

Unit conversion


Pharmacy sig code conversion


Refill reminder with refill date

General calculator


Tips in calculation

Preventing errors

  • Handwriting must be legible for any person to read
  • A pharmacist should never guess at the meaning of an unclear work or an abbreviation that may be a shorthand creation of the individual prescriber
  • Avoid the use of certain traditional abbreviations
  • Always using the metric system
  • Clear drug information. Name, metric weight or concentration, type of dosage form.
  • A leading zero before the decimal point. (.5 mg x , 0.5 mg)
  • Have properly placed commas (e.g., 4123 mL x, 4,123 mL)
  • Prescribers shall provide the weight of the patient when possible (dose check).
  • Provide a notation of purpose of the medication when possible
  • Should not use imprecise instructions (e.g., take as needed)
  • Writing or computer prescription is preferred
  • If a prescription has omitted the desired drug strength or its dosage form, pharmacist should never dispense the prescription but consult the prescriber
  • To avoid error in liquid dosing, a calibrated measuring device should be dispensed with the liquid medication.
  • Five rights principle: 1), the right medication; 2) the right dose; 3) the right patient; 4) the right time, and 5) the right route of administration

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