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Ibuprofen Dosage Calculator

Enter the patient weight to get the correct ibuprofen dose in milligrams, the matching liquid volume for common suspension concentrations, the number of tablets needed, and the maximum daily dose. Switch between child and adult mode, metric and imperial weight, liquid and tablet forms.

Your details

Dosing strategy differs: children use weight-based dosing, adults use standard fixed doses.
Body weight is the most reliable basis for ibuprofen dosing.
kg
Age helps flag eligibility. Ibuprofen is not recommended for children under 6 months.
years
Standard 5 mg/kg is suitable for mild pain or low fever. High 10 mg/kg (max 400 mg) is the upper limit used for more significant pain or fever - always use the lowest effective dose.
Choose the product you have on hand to get the exact volume or count needed per dose.
Ibuprofen can be given every 6-8 hours. Every 8 hours is preferred to minimize GI exposure.
Single doseLow dose
100mg

Ibuprofen per dose (rounded to the nearest practical amount)

Maximum daily dose800mg
Liquid volume per dose5mL
Liquid volume (teaspoons)1tsp
Tablets per dose-
Doses per day3doses
Interval between doses8hours
Weight (for reference)20kg
100 mg
Low<200Standard200-400Rx - moderate400-600Rx - high600+

Safe dose: 100 mg every 8 hours (max 800 mg/day).

  • Dose of 100 mg equals approximately 5.0 mg/kg for this child.
  • Give every 8 hours as needed, up to 3 doses per day - total daily ibuprofen should not exceed 800 mg.
  • Always measure liquid ibuprofen with an oral dosing syringe, not a kitchen spoon - household spoons vary significantly in volume.
  • Take ibuprofen with food or milk to reduce the chance of stomach upset.

Next stepIf fever or pain does not improve after 2 days, or worsens at any point, contact your child's doctor.

How ibuprofen dosing works

Ibuprofen (sold as Advil, Motrin, Nurofen and generic brands) is a non-steroidal anti-inflammatory drug (NSAID) used to relieve pain, reduce fever, and ease inflammation. For children, the dose is always calculated from body weight, not age alone. The standard pediatric dose is 5 mg per kilogram of body weight per dose for mild symptoms, or up to 10 mg/kg for more significant fever or pain, with a hard ceiling of 400 mg per single dose. Adults use fixed doses of 200-400 mg over the counter, or 600-800 mg under a doctor's prescription. The total amount given in 24 hours is as important as the single dose. Children should not receive more than 40 mg/kg per day, and that figure is further capped at 1,200 mg daily. OTC adult dosing caps at 1,200 mg daily; prescription regimens can go up to 3,200 mg under physician supervision. This calculator applies all three limits automatically and shows the result that is safest within those constraints.

Choosing the right ibuprofen product

Different products have different concentrations, and mixing them up is one of the most common causes of accidental overdose. The two most widely available pediatric liquid forms are children's suspension (100 mg per 5 mL, equivalent to 20 mg/mL) and infant drops (50 mg per 1.25 mL, equivalent to 40 mg/mL). Because infant drops are twice as concentrated, the volume needed is half as large - a parent switching from drops to suspension without realizing it can accidentally double the dose. Chewable tablets come in 50 mg and 100 mg strengths and are suitable for children old enough to chew them safely (usually around 6 years old). Adult tablets of 200 mg and 400 mg are appropriate for adults and older teenagers. Prescription tablets of 600 mg and 800 mg are for physician-supervised regimens only. This calculator shows the correct volume or count for whichever product you select, so you always know exactly how much to measure out.

When ibuprofen should not be used

Ibuprofen is not suitable for all situations. It should not be given to infants under 6 months old or weighing less than 5 kg (11 lb) unless directed by a doctor. It is generally avoided in people with active stomach ulcers, significant kidney or liver disease, or a known allergy to NSAIDs. In pregnancy it is not recommended in the third trimester. People taking blood thinners, other NSAIDs, or high-dose aspirin should check with their doctor before using ibuprofen. Pediatricians also advise avoiding ibuprofen during chickenpox due to a rare association with serious skin infections. For most healthy people, short-term use at the lowest effective dose is safe. The key phrase is "lowest effective dose for the shortest necessary time." If a child's fever or pain is not controlled by the OTC dose, or if symptoms persist beyond 2 days (or 3 days for fever), it is time to contact a healthcare provider rather than increase the dose.

Dosing tips and measuring safely

Accurate measurement matters more than most people realize. A kitchen teaspoon can hold anywhere from 3 to 7 mL, so using it instead of a calibrated oral syringe can deliver anywhere from 60% to 140% of the intended dose. Always use the dosing syringe or cup that comes with the product, or buy a standalone oral syringe. For very small volumes (under 2 mL), a 1 mL or 2 mL syringe is more accurate than a larger one. Ibuprofen is best taken with food or milk to reduce stomach irritation. If a dose is missed, take it as soon as you remember, but skip it if it is almost time for the next dose - do not double up. Avoid storing opened liquid ibuprofen in a car or warm place, as high temperatures can affect stability. Shake liquid suspensions well before each use, as the active ingredient can settle to the bottom.

Standard ibuprofen dosing reference

Weight (kg)Weight (lb)Dose at 5 mg/kgDose at 10 mg/kgChildren's liquid (100 mg/5 mL)Infant drops (50 mg/1.25 mL)
5-7 11-1525-35 mg50-70 mg1.25-1.75 mL0.63-0.88 mL
8-10 18-2240-50 mg80-100 mg2.0-2.5 mL1.0-1.25 mL
11-15 24-3355-75 mg110-150 mg2.75-3.75 mL1.38-1.88 mL
16-21 35-4680-105 mg160-210 mg4.0-5.25 mL2.0-2.63 mL
22-27 48-60110-135 mg220-270 mg5.5-6.75 mL2.75-3.38 mL
28-35 62-77140-175 mg280-350 mg7.0-8.75 mL3.5-4.38 mL
36+ 79+180-200 mg360-400 mg (capped)9.0-10 mL4.5-5.0 mL

Approximate doses for common pediatric weight bands at 5 mg/kg and 10 mg/kg. Always prefer weight-based calculation over age alone. Do not exceed 400 mg per dose or 1,200 mg per day for children.

Frequently asked questions

Can I give ibuprofen to a child under 6 months?

No. Ibuprofen is not recommended for infants younger than 6 months unless your doctor specifically instructs you to use it. The kidneys of very young infants are not mature enough to process NSAIDs safely. For fever or discomfort in infants under 6 months, contact your pediatrician - acetaminophen may be appropriate in some cases, but dosing must be confirmed with the doctor.

How often can I give ibuprofen to my child?

Ibuprofen can be given every 6 to 8 hours as needed. Every 8 hours (3 times per day) is generally preferred because it reduces the total number of doses and gives the stomach more time between exposures. Do not give more than 4 doses in 24 hours. If more frequent dosing seems necessary, that is a signal to call the doctor rather than to increase the frequency.

What is the difference between infant drops and children's suspension?

Infant drops are more concentrated: 50 mg per 1.25 mL (40 mg/mL). Children's suspension is less concentrated: 100 mg per 5 mL (20 mg/mL). Because infant drops are twice as potent by volume, you need half as much liquid for the same milligram dose. Never swap one for the other without recalculating the volume - this is a common source of dosing errors. This calculator shows the correct volume for whichever product you select.

Can I alternate ibuprofen and acetaminophen?

Alternating ibuprofen and acetaminophen (paracetamol) every 4 hours is sometimes suggested by pediatricians for persistent high fever or significant pain in children over 6 months. Because the two drugs work by different mechanisms, they can be given closer together than either alone. However, this approach increases the risk of dosing confusion and errors, so it should only be done with clear written guidance from your doctor about timing, doses, and duration.

What is the maximum ibuprofen dose for an adult per day?

For over-the-counter use, the maximum is 1,200 mg per day (typically three 400 mg doses, or six 200 mg doses). Prescription regimens under medical supervision can go up to 3,200 mg per day. Most adults with occasional pain or fever need no more than 400 mg every 6-8 hours. Taking higher doses increases the risk of gastrointestinal bleeding, kidney stress, and cardiovascular effects without proportionally greater pain relief.

Should ibuprofen be taken with food?

Yes. Taking ibuprofen with food, milk, or an antacid reduces the risk of stomach upset and irritation. On an empty stomach, ibuprofen can cause nausea, abdominal pain, and in long-term or high-dose use, ulcers and bleeding. If you consistently experience GI discomfort even with food, discuss switching to an enteric-coated formulation or a different pain reliever with your doctor.

How do I measure liquid ibuprofen accurately?

Always use the oral dosing syringe included with the product, or a calibrated measuring cup or spoon. A household kitchen teaspoon can hold anywhere from 3 to 7 mL - far too imprecise for a medicine where the dose matters. For doses under 5 mL, a 1 mL or 2 mL oral syringe is more accurate than a larger syringe. Shake the bottle before each use to redistribute any settled medication, and read the syringe at eye level with the liquid meniscus at the marked line.

Sources

Written by Dr. Priya Anand, MD, FACP Internal Medicine Physician · Boston, USA

Board-certified internist translating clinical evidence into precise, actionable health calculators for patients and clinicians alike.

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This tool provides general information and education, not professional advice. For decisions about your health, consult a qualified professional.

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