Weight-Based Emergency Drug Calculator
Calculate pediatric emergency drug doses for epinephrine, atropine, amiodarone, and naloxone by weight.
About this calculator
This calculator applies weight-based mg/kg dosing to four pediatric emergency medications: Epinephrine (0.01 mg/kg of the 0.1 mg/mL, i.e. 1:10,000, concentration), Atropine (0.02 mg/kg at 0.1 mg/mL), Amiodarone (5 mg/kg at 50 mg/mL), and Naloxone (0.1 mg/kg at 0.4 mg/mL) -- dosing conventions consistent with standard pediatric emergency dosing references (e.g. PALS-based dosing tables). Patient Weight and the selected Drug together determine Dose: Weight scales the dose linearly within a drug, while switching Drug changes which per-kilogram rate and concentration apply -- Amiodarone's 5 mg/kg is 500 times Epinephrine's 0.01 mg/kg, so the choice of Drug has a far larger effect on the final Dose than a realistic change in Weight ever would.
Volume to Administer converts Dose into a drawn-up volume using each drug's stated Concentration. Dose is bounded on both ends: it is capped at a Maximum Dose per drug (1 mg for Epinephrine, 300 mg for Amiodarone, 2 mg for Naloxone) so a large patient's calculated dose cannot exceed the adult ceiling -- when a patient's raw weight-based dose would exceed that ceiling, the Maximum Dose output shows the cap that was applied. Atropine's ceiling itself steps up with patient size, from a 0.5 mg child maximum to a 1.0 mg adolescent/adult maximum once weight passes roughly 25 kg (the weight at which the raw 0.02 mg/kg dose first reaches 0.5 mg), and Atropine alone also has a 0.1 mg minimum single dose -- below that floor, the dose is too small to reliably counter the vagal response and can instead trigger a paradoxical bradycardia, so the calculator raises any Atropine dose under 0.1 mg up to the floor rather than reporting the smaller raw number.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
Dose
0.1 mg
Volume to Administer
1 mL
How to Use This Calculator
- Enter the patient's actual body weight in kg — always use measured weight, not estimated weight, for emergency drug dosing.
- Select the Drug from the dropdown: Epinephrine (0.01 mg/kg), Atropine (0.02 mg/kg), Amiodarone (5 mg/kg), or Naloxone (0.1 mg/kg).
- Review the calculated Dose in mg and Volume to Administer in mL at the standard concentration shown.
- Note the Maximum Dose — the calculated dose is automatically capped at the adult (or, for Atropine, weight-appropriate) maximum. For Atropine, a dose below 0.1 mg is automatically raised to that minimum.
- Verify the Concentration displayed matches the preparation available; always double-check doses with a second clinician before administration.
How the result changes with Patient Weight
| Patient Weight | Dose | Volume to Administer |
|---|---|---|
| 5 | 0.05 mg | 0.5 mL |
| 7.5 | 0.08 mg | 0.75 mL |
| 15 | 0.15 mg | 1.5 mL |
| 25 | 0.25 mg | 2.5 mL |
What each input means
- Patient Weight
- Patient weight in kilograms — use actual body weight.
- Drug
- Select the emergency medication to dose.
How this is calculated
Worked example, using the default values
- Identify Input ParametersPatient Weight = 10, Drug = Epinephrine = 2 input(s) provided
- Calculate DoseDose0.1 = 0.1
- Calculate Volume to AdministerVolume to Administer1 = 1
- Calculate Concentration0.1 mg/mL (1:10,000) = 0.1 mg/mL (1:10,000)
Engine last updated . Checked against 12 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does changing the Drug affect the Dose so much more than changing the Weight?
Because each drug's per-kilogram dosing rate differs by orders of magnitude -- Amiodarone is dosed at 5 mg/kg while Epinephrine is dosed at 0.01 mg/kg, a 500-fold difference. Patient Weight scales the dose linearly within whichever drug is selected, but it cannot produce anywhere near that scale of change on its own, since the calculator's weight range only spans roughly 200-fold (0.5 kg to 100 kg).
What happens when a patient's weight-based dose exceeds the Maximum Dose?
The calculated Dose is capped at that drug's Maximum Dose -- for example, Epinephrine's dose is capped at 1 mg even if 0.01 mg/kg times the entered Weight would produce more. The Maximum Dose output always shows that drug's ceiling so you can see whether the displayed Dose reflects the raw weight-based calculation or the capped maximum. Atropine is the one drug whose Maximum Dose itself changes with Weight -- 0.5 mg at or under 25 kg, 1.0 mg above 25 kg -- reflecting the real child-vs-adolescent Atropine ceiling rather than a single fixed number.
Does this calculator enforce a minimum dose for any of the drugs?
Yes, for Atropine only: any calculated dose below 0.1 mg is raised to a 0.1 mg floor, matching published pediatric dosing guidance that specifies a 0.1 mg minimum single dose for Atropine to avoid a paradoxical bradycardic response at very low doses. The other three drugs (Epinephrine, Amiodarone, Naloxone) only have an upper Maximum Dose cap in this calculator, no lower floor.
How is Volume to Administer calculated from the Dose?
Volume to Administer divides Dose by the selected drug's Concentration in mg/mL -- for example, an Epinephrine dose of 0.5 mg at the standard 0.1 mg/mL concentration gives 5 mL to draw up. Always confirm the Concentration shown matches the actual vial or prefilled syringe available, since drugs like Atropine and Epinephrine exist in more than one commercial concentration.
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