Pharmacy tools
Dosage Calculator
Calculate a weight-based drug dose (mg/kg) and daily total from patient weight and frequency.
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Version 1.0.0 · Last reviewed
Tool
Result
Live output from your inputs
Enter values and calculate to see results.
How it worksShow guideHide guide
Introduction
The dosage calculator multiplies patient weight by an ordered mg/kg dose to estimate a single dose and daily total. Use it to double-check weight-based prescribing — not as a substitute for a pharmacist or clinician.
Disclaimer: This tool is for informational purposes only and is not professional medical, pharmaceutical, financial, or tax advice. Always verify doses with a licensed clinician or pharmacist.
Formula
Weight-based dose equals patient weight times the ordered milligrams per kilogram. Multiply by doses per day for the daily total.
- w — Patient weight (kg)
- d_kg — Ordered dose (mg/kg)
Step-by-step
- Enter the patient weight in kilograms.
- Enter the ordered dose in mg per kg.
- Set how many times the dose is given per day.
Worked example
A 70 kg patient ordered 10 mg/kg twice daily receives 700 mg per dose and 1,400 mg per day.
Use cases
- Estimate a single weight-based dose in mg
- Convert mg/kg orders into a daily total
- Cross-check pediatric or critical-care dose math
Frequently asked questions
Does this replace a drug reference?
No. Always confirm the drug, indication, renal/hepatic adjustments, and max dose with a licensed professional and an official reference.
Can I enter pounds?
Convert pounds to kilograms first (lb ÷ 2.2046). This tool expects kilograms for SI dosing conventions.
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