Dose Calculator
Calculate medication dose from a prescribed mg/kg amount, body weight, dosing frequency, optional liquid concentration, and optional maximum daily dose.
Results
This calculator only performs dose math from values you enter. It does not recommend medication, dosage, frequency, or treatment. Always use the prescribed dose or product label and confirm medication dosing with a qualified healthcare professional, especially for children, kidney/liver disease, pregnancy, older adults, or high-risk medicines.
Use this Dose Calculator to perform medication dose arithmetic from a dose that has already been provided by a prescription, medicine label, pharmacist, or qualified healthcare professional.
Important: This calculator does not recommend medicines or decide what dose is safe. Always verify medication name, dose, frequency, body weight, concentration, and maximum-dose instructions before taking or giving medicine.
Calculation Method
For a dose prescribed as mg/kg per dose:
Dose per administration = body weight (kg) × prescribed mg/kg per dose
Total daily dose = dose per administration × doses per day
For a dose prescribed as mg/kg per day:
Total daily dose = body weight (kg) × prescribed mg/kg per day
Dose per administration = total daily dose ÷ doses per day
For liquid medicine:
Volume per dose (mL) = required dose (mg) ÷ concentration (mg/mL)
Example
Suppose an existing instruction specifies 10 mg/kg per dose for a 20 kg person.
20 × 10 = 200 mg per dose
If the instruction is twice daily:
200 × 2 = 400 mg per day
This example demonstrates the arithmetic only. It does not confirm that 200 mg is appropriate for any particular medicine or person.
Important Safety Notes
mg/kg per dose and mg/kg per day are not interchangeable. Selecting the wrong basis can substantially change the calculated amount.
For liquid medicine, enter the exact mg/mL concentration shown on the label. Use an appropriate metric dosing device rather than a household spoon.
Do not rely on this calculator for emergency dosing, insulin adjustment, chemotherapy, IV medication titration, anesthesia, anticoagulants, opioids, sedatives, or other high-risk medication decisions.