Tylenol (Acetaminophen) Dosage Calculator
Enter your child's weight or select the adult product you are using to get a precise acetaminophen dose in milligrams, milliliters of liquid, or tablet count. The calculator applies the standard 10-15 mg/kg pediatric guideline for children and the established fixed-dose adult recommendations. It also shows the maximum safe daily dose and a full 24-hour dosing schedule.
Formula
Worked example
A child weighing 20 kg at the standard 10 mg/kg rate: 20 x 10 = 200 mg per dose. Using 160 mg/5 mL suspension: 200 / 32 = 6.25 mL. Maximum daily at 75 mg/kg: 20 x 75 = 1500 mg, or 7.5 doses, capped at 5 doses = 5 x 200 mg = 1000 mg/day.
Why weight-based dosing matters for children
Unlike adult medications that use fixed doses, acetaminophen for children and infants is calculated from body weight because children vary enormously in size. A toddler weighing 10 kg and a 10-year-old weighing 35 kg would receive very different amounts, and using age alone as a guide can result in under-dosing (ineffective) or over-dosing (potentially harmful). The standard range accepted by pediatricians and pharmacists is 10 to 15 mg of acetaminophen per kilogram of body weight per dose. Use 10 mg/kg for mild symptoms and 15 mg/kg for higher fever or more significant pain, always within the limits shown here.
Adult dosing: product strength and interval
Adult Tylenol products use fixed doses rather than weight calculations, because adults of most sizes fall within a range where a standard dose is both safe and effective. Regular Strength (325 mg per tablet) can be taken every 4 to 6 hours, Extra Strength (500 mg) every 6 hours, and the 8-Hour Extended Release (650 mg) every 8 hours. In all cases the absolute maximum is 4,000 mg in any 24-hour period, and many liver specialists recommend staying under 3,000 mg per day for ongoing or daily use. People who drink three or more alcoholic drinks a day should consult a doctor before using acetaminophen regularly, as the combination can increase liver stress.
Avoiding accidental double-dosing
Acetaminophen is an ingredient in hundreds of combination products: cold and flu tablets, nighttime sleep aids, sinus formulas, prescription pain medicines, and more. Taking two products that each contain acetaminophen at the same time is one of the most common causes of unintentional overdose. Before using any over-the-counter medicine alongside Tylenol, read the active ingredients label. If acetaminophen (sometimes listed as APAP, paracetamol, or acetaminophen) appears in another product you are already taking, do not add Tylenol on top of it unless the combined amount stays below the daily limit.
When to seek medical attention
Acetaminophen is effective for most mild to moderate pain and fever, but some situations require professional evaluation rather than self-treatment. See a doctor or go to an emergency room if: a fever in any child under 3 months reaches 100.4 F (38 C) or higher; fever in older children or adults exceeds 104 F (40 C) or has lasted more than 3 days; pain is severe, sudden, or accompanied by shortness of breath, chest pressure, or signs of a serious injury; or you suspect that more acetaminophen than the daily limit may have been taken. Acetaminophen overdose can cause serious liver damage, and early treatment with the antidote N-acetylcysteine (NAC) is most effective when given within hours of ingestion.
Children's acetaminophen dosing by weight (160 mg/5 mL suspension)
| Weight (kg) | Weight (lb) | Dose (mg) | Volume (mL) | Age (approx) |
|---|---|---|---|---|
| 2.7 | 6 | 27 | 0.8 | 0-3 months* |
| 4 | 9 | 40 | 1.25 | 4-5 months |
| 5.4 | 12 | 54 | 1.7 | 6-8 months |
| 6.8 | 15 | 68 | 2.1 | 9-11 months |
| 8 | 18 | 80 | 2.5 | 12-17 months |
| 10 | 22 | 100 | 3.1 | 18-23 months |
| 12 | 26 | 120 | 3.75 | 2-3 years |
| 16 | 35 | 160 | 5 | 4-5 years |
| 22 | 48 | 220 | 6.9 | 6-8 years |
| 27 | 60 | 270 | 8.4 | 9-10 years |
| 32 | 70 | 320 | 10 | 11 years |
| 43.5 | 96 | 400 | 12.5 | 12+ years (child product) |
Standard 10 mg/kg dose. Use a calibrated syringe, not a kitchen spoon. Consult a doctor for children under 3 months.
Frequently asked questions
How do I calculate the right Tylenol dose for my child?
Multiply your child's weight in kilograms by 10 mg for a standard dose or 15 mg for the maximum dose. For example, a 15 kg child gets 15 x 10 = 150 mg at the standard rate. If you have the 160 mg/5 mL oral suspension, divide the mg dose by 32 to get milliliters: 150 / 32 = 4.7 mL. This calculator does all of those steps for you automatically.
What is the maximum safe daily dose of Tylenol for adults?
The labeled maximum for healthy adults is 4,000 mg in any 24-hour period. Many hepatologists (liver specialists) recommend keeping daily use under 3,000 mg if you use it regularly, if you have any liver condition, or if you drink alcohol. Remember to count acetaminophen from all sources, including combination cold, flu, and pain products.
Can I give my infant Tylenol under 3 months of age?
Tylenol is generally not recommended for infants under 3 months without direct guidance from a pediatrician. For fever in a newborn or very young infant, a doctor visit is always the right first step because fever can signal a serious infection that needs diagnosis, not just symptom relief.
What is the difference between Regular Strength and Extra Strength Tylenol?
Regular Strength tablets contain 325 mg of acetaminophen each, and the usual adult dose is 2 tablets (650 mg) every 4 to 6 hours. Extra Strength tablets contain 500 mg each, and the usual dose is 2 tablets (1,000 mg) every 6 hours. Extra Strength provides a higher dose per administration but must be spaced further apart to keep the daily total within the 4,000 mg limit.
How long does Tylenol take to work, and how long does it last?
Regular liquid or tablet acetaminophen typically begins reducing fever and pain within 30 to 45 minutes of ingestion and its effect lasts about 4 to 6 hours, which matches its dosing interval. The 8-hour extended-release formulation is designed to work over a longer window with a single administration.
Is it safe to take Tylenol every day?
Short-term daily use (a few days) is generally safe for healthy adults at recommended doses. Long-term daily use should be discussed with a healthcare provider because chronic high-dose acetaminophen use is a leading cause of liver failure in the US. If you need daily pain relief for weeks or months, a doctor can suggest the best strategy for your situation.