Children's Acetaminophen (Tylenol) Dose by Weight Calculator
Weight-based acetaminophen (paracetamol) dose for a child: milligrams per dose at 10-15 mg/kg, the millilitres of the 160 mg/5 mL US liquid or the UK 120 mg/5 mL and 250 mg/5 mL liquids, the maximum single and 24-hour amounts and how many doses fit in a day. For checking an over-the-counter dose, not for prescribing.
Last updated: October 2026
Not medical advice. This calculator gives an estimate for general information only. It is not medical advice and does not replace a doctor, pharmacist or other qualified health professional. Always check with them before acting on the result, especially for medication doses, children, pregnancy or a medical condition, and follow the guidelines of your local health authority.
Formula below · 4 sources (fda.gov, medlineplus.gov, healthychildren.org, nhs.uk) · Updated Oct 2026
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About this calculator
Children's acetaminophen (called paracetamol outside the US) is dosed by weight, not age: the usual oral dose is 10-15 mg per kilogram every 4-6 hours as needed, with no more than 5 doses in 24 hours. The American Academy of Pediatrics' dosing table and the Drug Facts label on US products are built on that rule, which is why the table's doses climb in 40 mg (1.25 mL) steps for infants and 80 mg steps for older children. This calculator multiplies the child's weight by the mg/kg you choose, caps a single dose at 1,000 mg (the adult maximum, reached only above about 67 kg at 15 mg/kg) and rounds to the nearest milligram.
Since 2011 every US children's and infants' liquid is the same strength, 160 mg per 5 mL (32 mg/mL), so the millilitres are the milligrams divided by 32. The UK sells two strengths: infant suspension 120 mg/5 mL for ages up to 5 and Six Plus 250 mg/5 mL for ages 6 and over. Chewable 160 mg tablets are for children aged 2 and over, and ordinary 325 mg tablets for 12 and over; the calculator rounds tablets down to a whole number so the dose never exceeds the weight-based figure. Always measure liquid with the oral syringe that came with the medicine, and check the strength on the bottle before using any figure from here.
The daily limit shown is 75 mg/kg in 24 hours and never more than 3,000 mg, the over-the-counter ceiling on current US labels (prescribers may allow up to 4 g in older children and adults). Babies under 3 months should not be given acetaminophen without a doctor's instructions, and any fever at that age needs same-day medical assessment, so the calculator gives no dose for that age group. Do not give 500 mg extra-strength products to children under 12 or 650 mg extended-release products under 18, and check that no other medicine the child takes (cold and flu remedies in particular) also contains acetaminophen. This tool is for checking an over-the-counter dose; it is not medical advice, and a pharmacist or doctor should confirm the dose for your child.
AAP weight-based dosing table for children's acetaminophen liquid, 160 mg per 5 mL (every 4 hours as needed, at most 5 doses in 24 hours)
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| Child's weight | Dose | Liquid 160 mg/5 mL | Chewable 160 mg tablets |
|---|---|---|---|
| 6-11 lb (2.7-5.0 kg) | 40 mg | 1.25 mL | — |
| 12-17 lb (5.4-7.7 kg) | 80 mg | 2.5 mL | — |
| 18-23 lb (8.2-10.4 kg) | 120 mg | 3.75 mL | — |
| 24-35 lb (10.9-15.9 kg) | 160 mg | 5 mL | 1 tablet |
| 36-47 lb (16.3-21.3 kg) | 240 mg | 7.5 mL | 1½ tablets |
| 48-59 lb (21.8-26.8 kg) | 320 mg | 10 mL | 2 tablets |
| 60-71 lb (27.2-32.2 kg) | 400 mg | 12.5 mL | 2½ tablets |
| 72-95 lb (32.7-43.1 kg) | 480 mg | 15 mL | 3 tablets |
How to use
Example: a 3-year-old who weighs 15 kg (33 lb), 15 mg/kg, children's liquid 160 mg/5 mL. Enter 15 kg, 2 to 11 years, 15 mg/kg and the 160 mg/5 mL product. Dose = 15 × 15 = 225 mg. Volume = 225 ÷ 32 = 7.0 mL. Maximum single dose 225 mg (15 mg/kg); maximum in 24 hours 15 × 75 = 1,125 mg, which allows 5 doses of 225 mg (1,125 mg) spaced at least 4 hours apart. The AAP table agrees: 24-35 lb is 5 mL and 36-47 lb is 7.5 mL, and 33 lb sits near the top of the first band, so 7 mL by weight is consistent. An 8-month-old of 8.5 kg at 12.5 mg/kg: 8.5 × 12.5 = 106 mg, which is 3.3 mL of the 160 mg/5 mL liquid or 4.4 mL of the UK 120 mg/5 mL infant liquid. A 13-year-old of 50 kg at 15 mg/kg: 750 mg per dose, with 325 mg tablets 2 tablets (650 mg, rounded down). The 24-hour maximum is capped at 3,000 mg, so 4 doses, not 5, fit in a day.
Frequently asked questions
How much acetaminophen can I give my child by weight?
The standard oral dose is 10-15 mg per kg of body weight every 4-6 hours, with no more than 5 doses in 24 hours. For a 10 kg (22 lb) child that is 100-150 mg, which is 3.1-4.7 mL of the 160 mg/5 mL liquid. US product labels and the AAP table give a fixed dose per weight band (for example 5 mL for 24-35 lb) that falls inside the same range. Weigh the child rather than guessing, and use the syringe supplied with the product.
How do I convert the dose from mg to mL?
Divide the milligrams by the concentration in mg per mL. All US children’s and infants’ acetaminophen liquid is 160 mg per 5 mL, which is 32 mg/mL, so 240 mg is 240 ÷ 32 = 7.5 mL. UK infant paracetamol is 120 mg/5 mL (24 mg/mL) and Six Plus is 250 mg/5 mL (50 mg/mL), so the same 240 mg would be 10 mL or 4.8 mL. The calculator does this for the product you select; always read the strength on the bottle you are holding.
Can I give acetaminophen to a baby under 3 months?
Not without a doctor’s instructions. The US labels say to ask a doctor for children under 2 years, and the AAP advises that any fever of 38 °C (100.4 °F) or more in a baby under 3 months needs medical assessment the same day, because it can be the only sign of a serious infection. In the UK, babies of 2-3 months may be given a small paracetamol dose after vaccinations on advice. The calculator deliberately shows no dose for the under-3-months age group.
What is the maximum dose of acetaminophen for a child in 24 hours?
Up to 5 doses in 24 hours for children under 12, which at 15 mg/kg is 75 mg/kg per day, and never more than the adult over-the-counter ceiling of 3,000 mg (some prescribers allow up to 4,000 mg). Doses must be at least 4 hours apart. Exceeding these limits risks liver injury, and the risk rises when a cold-and-flu product that also contains acetaminophen is given at the same time, so check every label for acetaminophen or APAP.
Can I alternate acetaminophen with ibuprofen?
Some clinicians advise alternating the two for a persistently uncomfortable child, since they act differently and ibuprofen can be given every 6-8 hours while acetaminophen can be given every 4-6. The AAP warns that alternating increases the chance of a dosing mistake, so if you do it, write down the time and medicine of every dose and keep each drug within its own limits. Ibuprofen is not for babies under 6 months; see the companion ibuprofen dose page.
Should I treat the fever at all?
Fever itself is not dangerous and helps fight infection; the aim of medicine is comfort, not a normal thermometer reading. Give a dose when the child is miserable, in pain or not drinking, and skip it when they are playing and drinking normally. Seek care regardless of the number for a baby under 3 months with any fever, a fever over 40 °C (104 °F) that does not come down, a rash that does not fade under pressure, a stiff neck, difficulty breathing, unusual drowsiness, a seizure or a fever lasting more than 2-3 days.
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Sources & references
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