Drug Calculations

Weight-Based Dose (mg/kg) Calculator

Turns an ordered mg/kg dose into the total dose, and into mL when you know the concentration.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Turn on JavaScript to use this calculator, or open it in the web app.

Formula

Dose (mg) = mg/kg × weight (kg)
Volume (mL) = dose (mg) ÷ concentration (mg/mL)

How it is used

• Weigh the patient in kilograms. Pounds ÷ 2.2 = kilograms; using a pound value as kilograms more than doubles the dose.
• For children without a known weight, use a length-based resuscitation tape.
• Check the concentration on the vial every time: epinephrine comes as 1 mg/mL and 0.1 mg/mL, and the wrong one is a tenfold error.

Key points

• Say the drug, dose, concentration and volume aloud and have a partner confirm before giving a high-alert medication.

Same formula as the app. Open it in the web app.

Related one-pagers

• Dosage Calculation for the ExamDose = mg/kg × kg: 15 × 30 = 450 mg.
• Toxidromes and AntidotesMethanol, ethylene glycol · Fomepizole 15 mg/kg IV, then 10 mg/kg every 12 h · Blocks alcohol dehydrogenase
• Newborn Care and ResuscitationEpinephrine IV/IO · 0.01 to 0.03 mg/kg (NRP start: 0.02) · Then 3 mL NS flush
• Pediatric Assessment and EmergenciesEpinephrine · 0.01 mg/kg IV/IO (0.1 mL/kg of 0.1 mg/mL), max 1 mg, every 3–5 min

Related calculators

• Desired Over Have
• Drip Rate (drops/min)
• mcg/kg/min to mL/hr
• Tablets or Capsules to Give

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.