Drug Dose by Weight (mg/kg → mL)
Converts weight-based dosing to administered volume using drug concentration
Calculator
Why use it
Prevents dosing errors in weight-based medications. Essential for pediatric drug calculations. Converts between units seamlessly. Quick bedside tool for emergency medications.
About
A universal weight-based dosing calculator that converts a prescribed dose (mg/kg) to the actual dose (mg) and volume to administer (mL) based on patient weight and drug concentration (mg/mL). Essential for pediatric dosing, emergency medications, and any weight-based drug calculation.
When to use
- Any weight-based medication dosing (mg/kg)
- Pediatric drug calculations
- Emergency medication administration
- Converting dose to volume for parenteral administration
Formula
Pearls & pitfalls
- Always verify units: mg/kg, mcg/kg, units/kg — they are NOT interchangeable.
- Double-check drug concentration on the vial/ampule label.
- For obese patients, consider ideal body weight (IBW) or adjusted body weight (ABW) for certain drugs.
- Maximum dose limits exist for many medications regardless of weight — always check.
- In pediatrics, decimal errors are a major safety concern — always double-check calculations.
- Some drugs use mcg/kg — convert appropriately (1 mg = 1000 mcg).
Next steps
Verify calculated dose against safe dose ranges (mg/kg/dose and mg/kg/day). Check for maximum single-dose limits. Consider renal/hepatic dose adjustments. Round to practical volumes for administration.
Evidence
Standard pharmaceutical calculation principles. ISMP (Institute for Safe Medication Practices) recommends independent double-checks for weight-based dosing, especially in pediatrics.
References
- Institute for Safe Medication Practices (ISMP). Guidelines for standard order sets and weight-based dosing. — link