This is not medical advice
This tool gives a general estimate based on commonly published dosing ranges. It does not replace the judgement of a pharmacist or doctor, and it does not replace the instructions on the medicine packaging or patient leaflet. Always check the product label for the exact concentration of your medicine. If you have any doubt at all, do not give the medication and ask a pharmacist or doctor first, especially for a baby or young child.
Select the active ingredient, the patient weight and age group to see an estimated dose range, daily maximum and minimum time between doses.
Estimated dosing
Check before you give this medicine
This estimate is not a prescription and does not replace a pharmacist, a doctor or the patient information leaflet of the exact product you have. Confirm the concentration (mg per mL or mg per tablet) on your product before measuring a dose. Never combine multiple medicines containing the same active ingredient. If in doubt, do not administer the medication and ask a health professional first.
How weight-based dosing works
Paracetamol and ibuprofen doses for children are commonly calculated from body weight, expressed as a certain number of milligrams per kilogram per dose, in line with the general approach used in NHS and BNF for Children guidance. This scales the amount to the size of the patient, which is why an accurate, current weight matters more than age alone. Adult dosing eventually flattens out to a fixed standard dose rather than continuing to rise with weight, which is why this tool always caps the result at the recognised adult maximum, even for a heavier patient.
What the ranges mean
- Paracetamol (acetaminophen), commonly dosed at 10 to 15 mg per kg per intake, up to four times in 24 hours, with at least 4 to 6 hours between doses, never exceeding the standard adult daily maximum of 4000 mg.
- Ibuprofen, commonly dosed at 5 to 10 mg per kg per intake, up to three or four times in 24 hours, with at least 6 to 8 hours between doses, never exceeding the standard adult over-the-counter daily maximum of 1200 mg. Ibuprofen is generally not recommended for babies under 3 months.
When to consult a professional instead of using a number
For a baby under 3 months, for a very low body weight, or for any child with a kidney, liver, heart or stomach condition, a general weight-based figure is not a safe substitute for individual medical advice. The same applies if the patient is already taking other medication, since combination cold and flu products often already contain paracetamol or ibuprofen, and doubling up is a common and dangerous mistake. In the UK, if a child appears seriously unwell after taking a medicine, or you suspect an overdose, call NHS 111 or, for an emergency, 999. The UK National Poisons Information Service is accessed by health professionals through TOXBASE; for immediate concern, contact NHS 111 or your nearest A&E.
This tool is not a medical device and does not provide a diagnosis or a prescription. It does not replace a pharmacist, a doctor or the patient information leaflet of your exact product. If you have any doubt, do not administer the medication and seek professional advice first. All calculations happen in your browser; nothing you enter is saved or sent anywhere.