Acetaminophen (Tylenol) Dosage Calculator
Calculate the correct acetaminophen (Tylenol, paracetamol) dose for adults and children based on weight and age.
Avoid dangerous overdose with accurate dosing.
What Is Acetaminophen?
Acetaminophen (known as paracetamol outside North America; brand name Tylenol) is one of the world’s most widely used pain relievers and fever reducers. Unlike ibuprofen, it does not reduce inflammation — it works by blocking pain signals in the brain and resetting the body’s temperature thermostat in the hypothalamus.
How It Works in the Body
Acetaminophen is metabolized primarily in the liver. At normal doses, it is broken down safely and excreted. At high doses, a toxic metabolite called NAPQI (N-acetyl-p-benzoquinone imine) is produced faster than the liver can neutralize it. NAPQI damages liver cells and can cause acute liver failure — the leading cause of acute liver failure in the United States.
Adult Dosing
Standard safe dose for healthy adults:
- 325–650 mg every 4–6 hours as needed, OR
- 1,000 mg every 6–8 hours (extra-strength)
- Maximum per day (healthy adults): 3,000–4,000 mg
- With liver disease or regular alcohol use: Maximum 2,000 mg per day
Pediatric Dosing
For children under 12:
- 10–15 mg per kilogram per dose
- Maximum per dose: 75 mg/kg/day or 5 doses in 24 hours, whichever comes first
- Dosing interval: Every 4–6 hours
- Common liquid concentrations: 160 mg/5 mL (children) or 32 mg/mL (infant drops)
The Hidden Acetaminophen Danger
Acetaminophen is found in hundreds of combination products: NyQuil, DayQuil, Theraflu, Percocet, Vicodin, Tramadol+Acetaminophen, and many prescription pain pills. Taking multiple products simultaneously is a common cause of accidental overdose. Always check every label for acetaminophen content and add up your total daily dose across all products.
Overdose Action
If you suspect an acetaminophen overdose, call Poison Control immediately: 1-800-222-1222 (US). Do not wait for symptoms — liver damage from overdose can be treated effectively if caught early (within 8–10 hours) with the antidote N-acetylcysteine (NAC).
Comparison to Ibuprofen
Acetaminophen: safer for kidneys, stomach, and cardiovascular system. Riskier for the liver. Does not reduce inflammation. Ibuprofen: reduces inflammation. Riskier for kidneys, stomach, and heart. Safer for the liver.
This calculator is for educational purposes only. Always follow product label directions and consult a healthcare provider.