Children’s Ibuprofen Dose Calculator

How it works

Dose = 5–10 mg/kg (max 400 mg; max 50 mg at 3–5 months) · volume = dose ÷ strength (mg/mL), rounded down to what the syringe measures · tablets = dose ÷ tablet strength, rounded down to a half (chewable) or whole (200 mg) tablet · 24-hour maximum = the lower of 40 mg/kg (US) or 30 mg/kg (UK) and 1,200 mg, in no more than 4 doses (US) or 3 doses (UK; 4 at 6–11 months)

Ibuprofen is dosed for children at 5–10 mg per kilogram, with at least six hours between doses. For a typical 15 kg three-year-old that is 75–150 mg, or 3.75–7.5 mL of the standard 100 mg/5 mL suspension. Dosing by weight is more accurate than the age bands on the packet, which assume an average-sized child, so the calculator shows both: the weight-based dose and the package-chart dose for comparison. Pick US rules (FDA label and AAP: every 6–8 hours, no more than 4 doses or 40 mg/kg in 24 hours, from 6 months) or UK rules (NHS and BNF for Children: up to 3 times a day, 4 at 6–11 months, no more than 30 mg/kg a day, from 3 months and 5 kg). Choose the product: 100 mg/5 mL suspension, the stronger 200 mg/5 mL suspension sold in many countries, 40 mg/mL infant drops, 100 mg chewable or 200 mg tablets, or any other liquid by its strength. Volumes are rounded down to what your syringe can measure, so the dose never goes above the calculated amount. Every dose is also capped at 400 mg and every day at 1,200 mg, the over-the-counter limit. Under More options you can enter the time of this dose to list the earliest times for later doses, and add a paracetamol (acetaminophen) dose if a doctor has advised alternating. Ibuprofen is not for babies under the minimum age, for a child who is dehydrated or vomiting, or with chickenpox. Fever itself is not dangerous; treat discomfort, not the number.

Worked example

A 15 kg three-year-old at 10 mg/kg: 10 × 15 = 150 mg, which is 150 ÷ 20 = 7.5 mL of the 100 mg/5 mL suspension (or 3.75 mL of the 200 mg/5 mL suspension or infant drops), every 6–8 hours. Under US rules the 24-hour limit is the lower of 40 × 15 = 600 mg and 1,200 mg, so no more than 4 doses of 150 mg. The US package chart for 33 lb (24–35 lb) gives 100 mg (5 mL). Under UK rules the limit is 30 × 15 = 450 mg, so 3 doses of 150 mg, and the NHS age band for 1–3 years is 100 mg.

Sources: HealthyChildren.org (AAP) — Ibuprofen dosing table for fever and pain · NHS — How and when to give ibuprofen for children · NIH/NLM DailyMed — Children’s ibuprofen oral suspension (OTC drug facts label) · KidsHealth (Nemours) — Ibuprofen dosage table

Frequently asked questions