Ibuprofen Dosage Calculator

Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that relieves pain and lowers fever. It is sold over the counter as Advil, Motrin and store brands. A child's dose is read from a weight and age chart on the label, not worked out with a formula, and from age 12 it is a fixed tablet dose.

What the Ibuprofen Dosage Calculator Measures

This tool is a label lookup. It shows what the current Drug Facts label lists for the product you pick. It does not replace the label, your doctor or a pharmacist. Advil and Motrin are brand names that belong to their owners, and this site is not affiliated with either brand.

The Formula

Dose = the label chart row that matches the child's weight (or age, if the weight is not known)

mg per dose = mL x 40 for infants' drops (50 mg per 1.25 mL), mL x 20 for children's liquid (100 mg per 5 mL), or tablets x 100 mg

Most in 24 hours (children) = dose x 4

Ages 12 and over = 1 tablet (200 mg) every 4 to 6 hours, 2 if 1 does not work, no more than 6 tablets (1,200 mg) in 24 hours unless a doctor says so

Rows and limits are copied from the current labels on DailyMed, the US National Library of Medicine's label database¹ ² ³ ⁴ ⁵.

How This Calculator Computes Your Result

Pick your product, enter the age, and add the weight in lb or kg if you know it. Kilograms are changed to pounds (1 lb = 0.45359237 kg) because the labels use pounds. Weight comes first, as the labels say: "If possible, use weight to dose; otherwise use age."¹ ² A weight between two printed rows, such as 17.6 lb, uses the lower row. All 100 mg chewables share one chart, while Junior Strength Advil swallow tablets have their own³ ⁴.

The result shows the dose in mL or tablets, its mg, how often, and the most in 24 hours. Under 6 months, or off the chart, it shows no number and says to ask the doctor.

What Your Result Means

These are the label charts the tool reads (mg per dose in brackets)¹ ² ³ ⁴.

Children's labels: repeat every 6 to 8 hours if needed, no more than 4 times a day¹ ² ³ ⁴. Adults and children 12 and over: 1 tablet "every 4 to 6 hours while symptoms persist," 2 if 1 does not help, and "do not exceed 6 caplets in 24 hours, unless directed by a doctor."⁵ Under 12, the adult label says "ask a doctor."⁵

Infants' Drops vs Children's Liquid

Infants' drops hold 40 mg per mL and children's liquid holds 20 mg per mL, so the same mL of drops gives twice the medicine⁶. The Institute for Safe Medication Practices (ISMP) reported a baby meant to get 70 mg who was given 3.5 mL of drops, a volume worked out for children's liquid. That is 140 mg⁶. The labels say to measure only with the syringe or cup in the box¹ ².

Ibuprofen Dose for a Child per kg

Over the counter labels do not print a mg per kg figure. The prescription label for ibuprofen oral suspension does, for ages 6 months up to 2 years: 5 mg/kg if the temperature is under 102.5°F or 10 mg/kg if it is 102.5°F or higher, 10 mg/kg every 6 to 8 hours for pain, and a "maximum daily dose" of 40 mg/kg⁷. By our arithmetic, the charts above give about 6.2 to 9.2 mg per kg at their printed weight limits. This is background only, and the tool never doses by mg per kg. The American Academy of Pediatrics (AAP) also says to dose by weight first and not to give ibuprofen under 6 months unless the doctor says to⁸.

Label Warnings That Matter Most

• Stomach bleeding. Ibuprofen "may cause severe stomach bleeding." The chance is higher with past ulcers, blood thinners or steroids, other NSAIDs, or taking more or longer than directed. For adults, it is also higher at age 60 or older and with 3 or more alcoholic drinks a day² ⁵. "Take with food or milk if stomach upset occurs."²

• Heart attack and stroke. "NSAIDs, except aspirin, increase the risk of heart attack, heart failure, and stroke."⁵ The FDA says this risk can start "as early as the first weeks" of use and appears greater at higher doses⁹.

• Kidneys and fluids. Ask a doctor first if the child "has not been drinking fluids" or "has lost a lot of fluid due to vomiting or diarrhea," or has kidney disease¹ ⁵. In 1,015 children with acute kidney injury, 27 cases were linked to NSAIDs, and 75% of those with dosing records had taken a dose within recommended limits¹⁰.

• Pregnancy. The adult label says not to use ibuprofen "at 20 weeks or later in pregnancy" unless a doctor says to⁵.

• When to stop. Ask a doctor if a child gets no relief within 24 hours, or fever or pain gets worse or lasts more than 3 days². For adults: pain over 10 days or fever over 3 days⁵.

If someone takes too much, call Poison Control at 1-800-222-1222 right away¹.