Ibuprofen Pediatric Dose Calculator

Pediatric OTC ibuprofen guidance uses a 5-10 mg/kg/dose range: 5 mg/kg is generally sufficient for a mild fever (under about 102.5°F), while 10 mg/kg is the usual dose for a higher fever or for pain. Both ends of the range are given every 6 to 8 hours. Choosing the lower end when appropriate is not a matter of caution alone — it is the labeled standard dosing pattern, not an arbitrary reduction.

Two independent safety ceilings apply to every ibuprofen dose calculation, and a calculator that only implements one of them can produce an unsafe number. The per-dose cap limits any single administration to 400 mg, which matters for heavier children whose raw weight × mg/kg math would otherwise exceed it. The daily cap limits the running total to 40 mg/kg/day, and this cap is binding even when each individual dose is comfortably under 400 mg — giving a 200 mg dose (well under the per-dose cap) six times in a day for a 20 kg child would total 1,200 mg, far above that child's 800 mg daily ceiling. This calculator checks both caps separately on every calculation and shows exactly which one, if either, reduced the raw number.

Ibuprofen is not given to infants under 6 months old without a clinician's guidance. Kidney function in this age group is still maturing, which makes ibuprofen clearance less predictable and raises the risk of kidney-related side effects even at a weight-appropriate dose. For this reason the calculator does not compute a dose number for that age band at all — it shows a caution instead and points toward speaking with the child's pediatrician or considering weight-based acetaminophen, which has a different age profile. A softer caution also applies under 2 years old or under about 12 lb (5.5 kg): a dose can still be calculated, but checking with the child's provider first is recommended.

Liquid ibuprofen is labeled as an amount per volume. The current standard children's suspension is 100 mg / 5 mL (20 mg/mL). Older infant-drop formulations were more concentrated at 50 mg / 1.25 mL (40 mg/mL) before most manufacturers reformulated them to match the standard strength in 2011, specifically to reduce dosing errors caused by mixing up the two concentrations. Some legacy-strength product can still be found, so always read the concentration printed on the specific bottle you have rather than assuming. Measure with an oral dosing syringe, not a household spoon, which can vary in volume by as much as 30%.

This tool performs the dosing arithmetic and applies the standard caps and age cautions only. It does not know about allergies, kidney or liver function, drug interactions, or other medications the child may be taking, and it cannot judge whether ibuprofen is the right choice for a specific child's symptoms. Always verify the dose with a pharmacist or the child's clinician, and read the current product label, before administering.