Calculate safe acetaminophen (paracetamol) dose by age and weight, with adult fixed dosing and weight-based paediatric dosing, daily limits, and liver-concern adjustments.
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Single dose range
325–1000
mg per dose
Frequency
Every 4–6 hours
Max per day
6 doses
Max daily dose
4000 mg
Population
Adult
• Do not exceed the maximum daily dose. Space doses at least 4–6 hours apart.
• If you consume 3 or more alcoholic drinks per day, ask a doctor about acetaminophen.
Medical disclaimer
This calculator provides general dosing guidance only. Always read the product label and consult a pharmacist or doctor before giving acetaminophen, especially to children under 12 or those with medical conditions.
Also in Medication
Health — Medication
Acetaminophen (paracetamol) is one of the most widely used analgesics and antipyretics worldwide. Understanding the correct dose for your age and weight — and the maximum safe daily limit — is essential to avoid accidental overdose, which is the most common cause of acute liver failure in the UK and US.
Adults and children weighing 50 kg or more typically use a fixed dose of 325–1,000 mg every four to six hours, up to a maximum of 4,000 mg per day for healthy adults (or 2,000 mg per day if liver health is a concern). Children under 50 kg use weight-based dosing of 10–15 mg per kilogram per dose, given up to five times per day.
Children under two years should not receive acetaminophen without medical supervision, as dose precision is critical at very low body weights.
Acetaminophen is metabolised by the liver. In standard doses it is safe for most people, but overdose — even unintentional cumulative overdose from combining multiple products — can cause serious liver damage. Those with liver disease, heavy alcohol use, or malnutrition face a lower safety threshold (typically 2,000 mg per day maximum).
Check all cold, flu, and combination analgesic products for hidden acetaminophen content before adding additional doses.
Frequently asked questions
The maximum single dose is 1,000 mg and the maximum daily dose is 4,000 mg for healthy adults — so no more than four 1,000 mg doses per day, each spaced at least four to six hours apart.
Acetaminophen has traditionally been considered the analgesic of first choice in pregnancy, but recent observational studies suggest caution. Use the lowest effective dose for the shortest time and consult your midwife or doctor.
The liver breaks down acetaminophen via multiple pathways. In liver disease or chronic heavy alcohol use, the detoxification pathways are impaired, so toxic metabolites can accumulate at lower doses than in healthy individuals.
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