01Niche tool
Fever and weight-based dosing
A reference, not a prescription. Dose by weight rather than by age, check the concentration on the bottle in your hand, and never medicate a fever in a baby under three months.
- Acetaminophen15 mg/kg every 4 to 6 hours
- Ibuprofen10 mg/kg every 6 to 8 hours
- Under 3 monthsAny fever is an emergency evaluation
- Poison Control1-800-222-1222, 24 hours
02
The calculator
Enter your child's age band and weight. The tool refuses to produce a dose where a dose would be unsafe, which is the point.
If this is a medical emergency, or your child is struggling to breathe, unresponsive, having a seizure, or badly injured, call 911 now. Call 911.
Work out a dose
Enter a weight measured in the last three months. Always check the concentration printed on the bottle in your hand.
Poison Control: 1-800-222-1222, free and open 24 hours.
Under 3 months with any fever
A rectal temperature of 100.4 F or 38 C or higher in a baby under 3 months is an emergency evaluation, not a dose of medicine. Go to a pediatric emergency department and call us on the way.
Treat the child, not the number
Fever is the immune system working. We medicate for comfort, not to hit a target temperature. A child who is drinking, weeing and playing at 102 F is doing better than a listless child at 100 F.
Do not alternate on a timer
Alternating acetaminophen and ibuprofen every few hours is where dosing errors happen. If your child needs both, write down what you gave and at what time, and call us.
Weigh, do not guess
Use a weight from the last 3 months. A dose worked out from a weight your child had last year is the most common preventable dosing error we see.
What the bottles actually contain
Acetaminophen (Tylenol and store brands)
- 15 mg per kg of body weight per dose
- Every 4 to 6 hours, maximum 5 doses in 24 hours
- Do not give to a baby under 3 months without speaking to us first
Infant and children's liquid, 160 mg per 5 mL. The single concentration sold in the United States since 2011. Always check the bottle.
Chewable tablet, 160 mg. Only for children who reliably chew and swallow tablets.
- Dose by weight, never by age. Age ranges on the box are an approximation.
- Use the syringe that came with the bottle. Kitchen teaspoons are not a measuring device.
- Check every other medicine your child is taking for acetaminophen. Combination cold products are the usual route to an overdose.
Ibuprofen (Motrin, Advil and store brands)
- 10 mg per kg of body weight per dose
- Every 6 to 8 hours, maximum 4 doses in 24 hours
- Not for babies under 6 months
Infant drops, 50 mg per 1.25 mL. Concentrated. Very easy to confuse with the children's liquid.
Children's liquid, 100 mg per 5 mL. The usual bottle for children over 2.
- Give with food or milk. Ibuprofen on an empty stomach upsets children's stomachs.
- Avoid in dehydration, vomiting that will not stop, or known kidney problems.
- Not for babies under 6 months, and not for chickenpox without talking to us.
General information, not medical advice. It is not tailored to your child and it does not replace a visit. Confirm any dose with our nurse line or your pharmacist before you give it.
03
Where to take this, tonight
Our nurses use pediatric protocols. This is roughly how the conversation sorts out.
Call 911 now
- Struggling to breathe, grunting, or blue around the lips
- Unresponsive, limp, or impossible to wake
- A seizure that is still going after 5 minutes, or a first seizure
- A head injury with vomiting, confusion or loss of consciousness
- Purple spots that do not fade when you press a glass against them
- Any thought of self-harm: call or text 988, or 911 if there is immediate danger
Emergency department tonight
- Any fever in a baby under 3 months
- Dehydration: no wet nappy for 8 hours, no tears, sunken eyes
- A cut that will not stop bleeding after 10 minutes of pressure
- Severe abdominal pain, especially with vomiting that is green
- A limb that looks deformed, or a child refusing to bear weight
Call us at 7:30am
- Fever over 3 days, or a fever that returns after a day without one
- Ear pain, sore throat, or a cough keeping everyone awake
- A rash that is spreading but the child is otherwise well
- Vomiting or diarrhoea that is settling but not gone
- An asthma flare needing rescue inhaler more than every 4 hours
Manage at home, message us
- A runny nose with a good appetite and normal activity
- One or two days of low fever in a child who is drinking and playing
- Mild nappy rash or teething discomfort
- A single vomit with no fever and normal behaviour after
- Questions about a medication refill or a form
Poison Control: 1-800-222-1222, free and open 24 hours. 988 Suicide and Crisis Lifeline: call or text 988.
General information, not medical advice. It is not tailored to your child and it does not replace a visit.
04
The six mistakes we see most
None of these come from carelessness. They come from being awake at 3am with a hot child.
Dosing from last year's weight
The most common preventable error we see. Use a weight measured in the last three months, or weigh your child at home before you dose.
The kitchen teaspoon
A teaspoon from a drawer is not a measuring device and varies by up to 50 percent. Use the syringe or cup that came with the bottle.
Doubling up without knowing
Combination cold and flu products almost all contain acetaminophen. Read every label before you give anything alongside it.
Alternating from memory at 4am
If your child needs both medicines, write the drug, dose and time on paper on the kitchen counter. Do not run the schedule in your head.
Ibuprofen in a dehydrated child
Ibuprofen is hard on the kidneys when a child is not keeping fluids down. Use acetaminophen, and call us if vomiting will not stop.
Treating a number instead of a child
A child at 102 F who is drinking, weeing and playing does not need medicine. A listless child at 100 F needs a phone call.
05
Questions about fever
Still not sure? That is exactly what the nurse line is for, and nobody minds the call.
How the nurse line worksHeight alone does not decide it. The exceptions are age-based: any fever in a baby under three months is an emergency evaluation, and a temperature over 104 F at any age is worth a call. What matters far more is how your child looks between fevers, how they are drinking, and how they are breathing.
A simple febrile seizure is frightening and usually harmless, and fever medicine does not prevent one. Call 911 for a seizure lasting more than five minutes, a first seizure, or a child who does not return to normal afterwards.
Sometimes, for a child who is genuinely uncomfortable. Do not run them on a rotating timer from memory. Write down each dose and the time, and call our nurse line rather than guessing.
Never give aspirin to a child or teenager with a fever or a viral illness because of the risk of Reye syndrome, unless a clinician has specifically told you to for another reason.
Call Poison Control on 1-800-222-1222 straight away. It is free, open 24 hours and staffed by specialists. They are not going to judge you, and they would rather hear from you early.
When in doubt, call rather than dose
A pediatric nurse answers our line 24 hours a day and will work through it with you. If this is a medical emergency, call 911 instead.