Figuring out the right amount of Tylenol (acetaminophen) for your baby or toddler can feel stressful — especially at 2am with a fussy, feverish child. This guide provides weight-based dosage information following standard pediatric dosing guidelines.
Quick answer: Acetaminophen is dosed at 10-15 mg per kilogram of body weight, given every 4-6 hours as needed, with a maximum of 5 doses in 24 hours.
For a personalized calculation based on your child’s exact weight, use our free dosage calculator.
Acetaminophen (Tylenol) Dosage Chart by Weight
| Weight | Age (approx.) | Dose | Infant Drops (160mg/5mL) | Children’s Liquid (160mg/5mL) |
|---|---|---|---|---|
| 6-11 lbs | 0-3 months | 40 mg | 0.4 mL* | — |
| 12-17 lbs | 4-11 months | 80 mg | 0.8 mL | 2.5 mL |
| 18-23 lbs | 12-23 months | 120 mg | 1.2 mL | 3.75 mL |
| 24-35 lbs | 2-3 years | 160 mg | — | 5 mL |
| 36-47 lbs | 4-5 years | 240 mg | — | 7.5 mL |
*For infants under 3 months, always consult your pediatrician before giving acetaminophen.
Key Safety Rules
- Always dose by weight, not age — weight is more accurate
- Never exceed 5 doses in 24 hours
- Wait at least 4 hours between doses
- Use the measuring device that comes with the medication — kitchen spoons are not accurate
- Check the concentration — infant drops and children’s liquid may have different concentrations depending on the brand
When to Call Your Pediatrician
Contact your doctor if:
- Your baby is under 3 months with any fever (100.4°F / 38°C or higher)
- Fever persists for more than 3 days despite medication
- Your child seems unusually lethargic or difficult to wake
- You’re unsure about the dose for your child’s weight
Want structured guidance? TriageNest’s symptom triage walks you through age-specific questions and tells you exactly when to call your doctor, when to monitor at home, and when to seek immediate care.
What About Ibuprofen?
Ibuprofen (Motrin/Advil) is another option for children 6 months and older. Some pediatricians recommend alternating Tylenol and Motrin for persistent fevers. Check our Motrin dosage guide for weight-based ibuprofen dosing.
Common Questions
Can I give Tylenol to my newborn?
For infants under 3 months, you should always consult your pediatrician before giving any medication. A fever in a very young baby (100.4°F or higher) requires medical evaluation regardless of whether medication is given.
What if my child vomits after taking Tylenol?
If your child vomits within 15-20 minutes of taking the dose, you can generally re-dose. If it’s been more than 20 minutes, the medication has likely been absorbed. When in doubt, call your pediatrician.
How long does Tylenol take to work?
Acetaminophen typically starts reducing fever within 30-60 minutes and peaks at about 2-3 hours. It usually lasts 4-6 hours.
This article provides general guidance based on standard pediatric dosing practices. It is not a substitute for your pediatrician’s advice. For personalized symptom assessment and medication guidance, try TriageNest free.
