Child medicine dose calculator by weight
One calculator for both fever medicines. Enter the weight, find your product's strength in the table and read the millilitres. The numbers come from the mg/kg ranges in manufacturers' leaflets.
Last updated: 24 September 2026
Paracetamol (acetaminophen)
kg
Ibuprofen
kg
When can the next dose be given?
How to read the result
- Dose is the typical fever dose (15 mg/kg paracetamol, 10 mg/kg ibuprofen) rounded to syringe marks.
- Range is the full leaflet range; the lower end often suffices for mild pain.
- Daily limit comes from weight: 60 mg/kg paracetamol and 30 mg/kg ibuprofen, capped at 4 and 3 doses.
What a calculator cannot do
- Check what is on your bottle. Regular and Forte differ two- to fourfold.
- Remember when the previous dose was and who gave it.
- Know that your child has chickenpox, is vomiting, or is under 3 months. That is a doctor's job.
Check the official source
These numbers are conversions from leaflets and guidelines. Before giving a medicine, confirm them at the source:
- NHS: paracetamol for children · NHS: ibuprofen for children
- NICE NG143 — fever in under 5s · AAP HealthyChildren.org
- Polish medicines register (URPL) — official leaflets of the products listed here
- Your own country's medicines regulator and the leaflet in the box always take precedence.
Don't want to calculate and write this down every time?
Oh Fever does it from your child's profile and the product you use: it converts the leaflet dose to weight, counts down to the next dose and watches the daily limit — on iPhone and Apple Watch. Free for one child.
Read next
Sources
NHS — Paracetamol for children
NHS — Ibuprofen for children
American Academy of Pediatrics — Medications used to treat fever
Polish Register of Medicinal Products (URPL) — Summaries of Product Characteristics
This content is for information only and does not replace your doctor or the medicine leaflet. Doses on this page are the mg/kg ranges from manufacturers' leaflets converted to body weight. Check the strength on the package before giving any medicine. For high fever, any fever in an infant under 3 months, or worrying symptoms, contact a doctor.
NHS — Paracetamol for children
NHS — Ibuprofen for children
American Academy of Pediatrics — Medications used to treat fever
Polish Register of Medicinal Products (URPL) — Summaries of Product Characteristics
This content is for information only and does not replace your doctor or the medicine leaflet. Doses on this page are the mg/kg ranges from manufacturers' leaflets converted to body weight. Check the strength on the package before giving any medicine. For high fever, any fever in an infant under 3 months, or worrying symptoms, contact a doctor.