Dosage By Weight Calculator
Enter patient weight and dose per kg to instantly calculate the correct medication dose in mg or ml.
Use the Dosage By Weight Calculator
Patient & Dose Inputs
Prescribed mg per kg for a single dose. If prescribed as mg/kg/day, divide by doses per day first.
Used to calculate total daily dose.
Enter to convert mg dose to ml volume.
If the calculated dose exceeds this, a warning is shown.
Single Dose
Weight used
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Dose rate
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Total daily dose
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Enter weight and dose rate to see the result.
Disclaimer: This tool is for educational reference only. Always verify doses with a licensed pharmacist or physician before administration.
Summary
This dosage by weight calculator determines the correct medication dose based on the patient's body weight and the prescribed dose-per-kilogram value. Enter weight in kilograms or pounds, input the dose rate (mg/kg), and the tool instantly outputs the total dose in mg. If you know the medication concentration (mg/ml), it also converts to the volume in ml.
How it works
- Enter the patient's weight in kilograms or pounds.
- Input the prescribed dose rate in mg per kg per dose (mg/kg).
- Optionally enter the medication concentration in mg/ml.
- The calculator multiplies weight × dose rate to get the total mg dose.
- If concentration is provided, it divides total mg by mg/ml to give volume in ml.
- Results update instantly as you type — no button press needed.
Use cases
- Calculate pediatric medication doses based on child's weight.
- Verify adult antibiotic or analgesic dosing before administration.
- Convert a mg dose to ml for liquid medications or oral suspensions.
- Double-check a prescribed dose against standard mg/kg guidelines.
- Calculate ibuprofen or acetaminophen dose for children by weight.
- Assist nurses and caregivers with weight-based drug calculations.