π Pediatric Epinephrine Dose
Weight-based anaphylaxis dosing with auto-injector bands.
For informational purposes only, not medical advice. Consult a healthcare professional.
Epinephrine is the first and most important drug in anaphylaxis, and delay kills more surely than any dosing nuance. The pediatric intramuscular dose is 0.01 mg per kilogram of 1 mg/mL (1:1000) epinephrine into the mid-outer thigh, up to 0.3 mg in smaller children and 0.5 mg in adolescents. Auto-injectors simplify this to weight bands: 0.15 mg for 15 to 30 kg and 0.3 mg above 30 kg. This calculator shows both, for study and emergency reference. It does not replace calling emergency services or an allergy action plan.
How to Use This Calculator
Enter the weight in kilograms. The calculator gives the intramuscular dose used by clinicians and the auto-injector strength for home and school use.
Enter the weight. In an emergency use your best estimate; epinephrine underdosing from delay is worse than a slightly imprecise weight.
Read the IM dose: 0.01 mg per kg of 1 mg/mL epinephrine into the mid-outer thigh, capped at 0.3 mg for smaller children and 0.5 mg for larger ones.
Check the auto-injector band: 0.15 mg for 15 to 30 kg, 0.3 mg above 30 kg. Repeat every 5 to 15 minutes if symptoms persist, and always call emergency services.
How the Math Works
Multiply weight in kilograms by 0.01 to get milligrams of epinephrine, using the 1 mg/mL concentration, which makes the volume in mL numerically equal to the mg dose. A 20 kg child gets 0.2 mg, which is 0.2 mL. Apply the caps: 0.3 mg maximum for prepubertal children and 0.5 mg for adolescents and adults, per anaphylaxis guidelines. Doses repeat every 5 to 15 minutes as needed. Auto-injector bands come from device labeling: 0.15 mg for 15 to 30 kg, 0.3 mg for over 30 kg, with some guidelines extending 0.15 mg down toward 7.5 to 15 kg at clinician discretion.
Worked Example
A 20 kg child with anaphylaxis needs 0.20 mg of 1 mg/mL epinephrine intramuscularly into the mid-outer thigh, which is 0.20 mL of volume since the concentration is 1 mg per mL. That is under the 0.3 mg cap, so no capping applies. For home use the calculator recommends the 0.15 mg auto-injector, and the dose can repeat in 5 to 15 minutes while waiting for paramedics.
Reading Your Result
Give epinephrine at the first sign of systemic anaphylaxis: breathing difficulty, throat tightness, dizziness, or multi-system hives with vomiting. Intramuscular in the thigh beats subcutaneous and beats waiting. Antihistamines and steroids are adjuncts, never substitutes, and anyone who needed epinephrine needs emergency evaluation for biphasic reactions hours later. If the first dose does not help within 5 to 15 minutes, give a second; needing repeated doses is common, not a failure.
| Situation | Dose | Notes |
|---|---|---|
| IM, clinical setting | 0.01 mg/kg | Max 0.3 mg child, 0.5 mg teen |
| Auto-injector 15-30 kg | 0.15 mg | Mid-outer thigh, through clothing OK |
| Auto-injector over 30 kg | 0.3 mg | Repeat 5-15 min as needed |
Limitations
This is emergency reference information, not a substitute for an allergy action plan from the child allergist or for calling emergency services. Weight estimates in a crisis are approximate by necessity. IV epinephrine dosing is a different, intensive-care calculation and must never be improvised from IM numbers. Children under 15 kg need clinician guidance on auto-injector choice.
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For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is the epinephrine dose for a child with anaphylaxis?
0.01 mg per kilogram intramuscularly, using 1 mg/mL epinephrine, up to 0.3 mg in younger children and 0.5 mg in adolescents. For auto-injectors: 0.15 mg for 15 to 30 kg, 0.3 mg above 30 kg. Repeat every 5 to 15 minutes if needed.
Where do you inject epinephrine?
Mid-outer thigh, intramuscular. It absorbs faster and more reliably there than in the arm or buttock, and auto-injectors are designed for it. Inject through clothing if needed; do not waste time removing pants in an emergency.
Can you give too much epinephrine?
Side effects like fast heartbeat, tremor, and pallor are common and transient at correct doses. Dangerous overdoses come from IV dosing errors or repeated large doses, not from a single correct IM dose. Withholding epinephrine from real anaphylaxis is far riskier than giving it.
When should I use the auto-injector versus waiting?
Use it at the first sign of a systemic reaction: trouble breathing, throat tightness, dizziness, faintness, or hives plus vomiting or gut symptoms. Waiting to see if it gets worse is the classic error. Epinephrine works best early, and you cannot take back a delay.
Do antihistamines replace epinephrine?
Never. Antihistamines like diphenhydramine do not stop anaphylaxis and do not prevent biphasic reactions. They are an optional add-on after epinephrine, not an alternative. Steroids are similarly secondary. Epinephrine first, always.
What is a biphasic reaction?
A second wave of anaphylaxis hours after the first episode resolves, occurring in a minority of cases. It is why everyone treated for anaphylaxis needs emergency department observation for several hours even after feeling better. A second auto-injector should be available during the wait.
How do I use an auto-injector?
Press firmly against the mid-outer thigh until it clicks, hold for the labeled time (usually 3 to 10 seconds depending on brand), then remove and massage the area. Note the time given. Different brands have different hold times, so read your specific device before an emergency.
Does epinephrine expire?
Yes, typically 12 to 18 months. Expired devices lose potency gradually rather than becoming harmful, and guidelines say an expired injector beats none in a crisis, but replace them on schedule. Heat degrades them faster, so do not store them in hot cars.
What about children under 15 kg?
Standard auto-injectors start at 0.15 mg for 15 kg and up. Below that, the allergist decides: some prescribe the 0.15 mg device anyway since the alternative is no epinephrine, others use drawn-up doses. This needs an individual plan, not a calculator default.
Should schools keep epinephrine?
Many jurisdictions now allow or require undesignated stock epinephrine in schools with trained staff. A child with known anaphylaxis needs a personal action plan and their own device at school. Ask the school nurse about their protocol before the school year starts.