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Cefdinir Dose Calculator

Created by Aleksandra Zając, MD
Reviewed by Anna Szczepanek, PhD and Adena Benn
Based on research by
Omnicef (cefdinir) SmPC;; June 2007
Last updated: Jan 18, 2024

Suppose you suffer from an acute infection, such as a sinus infection - you might want to use our cefdinir dose calculator to learn more about the drug. In the text, you'll get familiar with Omnicef dosage (cefdinir dosage), indications for cefdinir, and what diseases can be cured with that drug. Also, stay if you're a parent of a child to receive it - know the cefdinir pediatric dose, how to calculate pediatric dose of the proper solution, and what are maximal daily doses.

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace professional medical advice, diagnosis, or treatment. All information on this website is for informational purposes only and is not intended to and should not serve as a substitute for medical consultation. Always seek the advice of a health provider.

What is Omnicef (cefdinir)?

Cefdinir is a type of antibiotic used to treat bacterial infections. It comes from the cephalosporins family. Cefdinir kills bacteria by distorting their cell membrane.

Cefdinir (or Omnicef - the brand name) is intended for oral use. It does not work when used topically.

Omnicef dosage for adults

Cefdinir doses for adults don't require any additional calculations. You need to check the indication to adjust the dose and the timing. For most common infections, like a sinus infection or otitis media, the dose is 300 mg every 12 hours (twice a day) or 600 mg every 24 hours (once a day). There are two exceptions: pneumonia and skin infections are better treated with 300 mg every twelve hours with no option to reduce it to one-a-day-dosing.

For patients with eGFR (estimated glomerular filtration rate) decreased to <30 mL/min/1.73 m², the recommended dose is 300 mg of cefdinir once a day. The maximum dose of 600 mg doesn't apply here.

Don't know the GFR value? Use our GFR calculator!

Pediatric cefdinir dose - cefdinir dose by weight - pediatric ear infection example

Children under 12 years old and weighing a maximum of 42 kg (92.6 lbs) should receive cefdinir by weight. Depending on the indication, the usual dose is 7 mg per kg every 12 hours or 14 mg per kg every 24 hours.

In case of kidney disease and creatinine clearance <30 mL/min/1.73 m², the cefdinir pediatric dose should not exceed 7 mg/kg once a day.

Note that if the child is heavier than 42 kg (42.7 kg to be super precise), the dose will stop at 300 mg twice a day or 600 mg once a day. Our cefdinir dose calculator takes that into account as well.

Omnicef comes in three different forms:

  • Omnicef 300 mg capsules;
  • Omnicef powder for suspension 125 mg/5 ml; and
  • Omnicef powder for suspension 250 mg/5 ml.

If you need to give a child suspension (because 300 mg of a drug is too much and you have to measure), you'll need the dose and the amount of the solution in the proper strength. You can count that on your own or by using our calculator. Let's solve an example.

Timmy is four and weighs 22 kg (48.5 lbs). He's been suffering from otitis media for the past two days. He's in good condition, but the pediatrician decides it's time for the antibiotherapy. He recommends Omnicef (cefdinir). How much of a drug should Timmy receive? How much of the 125 mg/5 ml solution should he get?

  1. First, we check the indication. For pediatric ear infections, the dose of cefdinir is
    7 mg/kg every 12 hours; or
    14 mg/kg every 24 hours.

  2. Let's count the doses.
    7 × 22 = 154 mg (two doses a day)
    14 × 22 = 308 mg (one dose a day)

  3. Now, the amount of solution.
    To find out how much of a drug there is in one milliliter of a solution, we divide 125 mg by 5 ml.
    125/5 = 25 mg/ml

    To calculate the amount of solution, we need to divide the desired dose by the amount in one milliliter.
    For two doses a day:
    154 mg / 25 mg/ml = 6.16 ml = ~6 ml

    For one dose a day:
    308 mg / 25 mg/ml = ~12.3 ml

How to use the cefdinir dose calculator?

To use our Omnicef (cefdinir) dose calculator:

  1. See the calculator panel on the left.
  2. Choose the age of the patient. Note: cefdinir is not intended for infants under six months old, even if indications such as sinus infection or otitis media (pediatric ear infection) are present.
  3. Input the indication for antibiotic use.
  4. If you've chosen a child as a patient, the calculator will ask you to provide the child's weight. The calculator counts the doses for children by weight. You can switch between kilograms and pounds - whatever is more comfortable.
  5. Again, choose the Omnicef solution strength if you've chosen a pediatric patient. This will give you the amount of the solution to give to the child.
  6. That's it! Your result is ready. Remember that you can change the solution's strength if you use a stronger or weaker formula.

Omnicef indications & practical use (cefdinir for UTI?)

Indications for the use of cefdinir include:

  1. Community-acquired pneumonia (CAP);
  2. Acute exacerbation of chronic bronchitis;
  3. Bacterial sinus infection (acute maxillary sinusitis);
  4. Acute bacterial otitis media (usually only in pediatric patients);
  5. Pharyngitis/tonsillitis; and
  6. Uncomplicated skin and skin structure infections.

In rare cases, your doctor can prescribe Omnicef for other types of infections. Some patients can receive cefdinir for UTI (urinary tract infection), especially if the first- and second-course drugs didn't work.

A doctor would usually prescribe cefdinir for 5 to 10 days of therapy.

❗ Always finish the whole course of antibiotherapy that the doctor prescribed, even if you don't feel symptoms anymore. Failure to complete the course causes the development of germs resistant to antibiotics.

Cefdinir will not work for viral infections, such as the flu, a common cold or COVID-19.

Precautions - maximal dose, accidental double dose of cefdinir

It's good to know the following when taking this drug:

  1. Maximal daily dose of Omnicef (cefdinir) for adults and children is 600 mg per day.
  2. Patients with chronic kidney disease with GFR <30 mL/min/1.73 m² should take no more than 300 mg of the drug per day.
  3. In case of an accidental double dose of cefdinir - contact the physician that prescribed you the drug. The risk of severe adverse effects after a bigger dose is minimal; however, staying on the safe side is better.
  4. You can take the drug regardless of meals. However, taking it with meals might decrease the chance of stomach upset. Be careful to take at least a one-hour break between cefdinir and dietary supplements containing iron or magnesium.


How do I count the maximum cefdinir dose for a 77 lb child?

The maximum daily cefdinir dose for a 77 lb child is 489 mg once every 24 hours or 244 mg every 12 hours.
To calculate it:

  1. Convert the weight in lbs to kgs. 77 lbs = 34.9 kg
  2. A standard dose of cefdinir for children is 7 mg/kg twice a day or 14 mg/kg once a day. Multiply the child's weight in kg by the doses.
    34.9 × 7 = ~244
    34.9 × 14 = ~489

How do I calculate cefdinir for strep throat dose for a 42 lb child?

The dose of cefdinir for strep throat for a 42 lb child is 133 mg every 12 hours or 267 mg every 24 hours.
How to count it?

  1. Check the dose for the specific indication. For pharyngitis in children, it's 7 mg/kg twice a day or 14 mg/kg once a day.
  2. Convert the child's weight to kilograms. 42 lbs = 19.05 kg
  3. Multiply the weight with the proper dose.
    7 × 19.05 = 133 (twice a day dosing); and
    14 × 19.05 = 267 (once a day dosing).

Can I drink alcohol on cefdinir?

You shouldn't combine cefdinir therapy with alcohol consumption. It can have dangerous health consequences. You might experience exacerbated side effects, e.g., drowsiness, dizziness, vomiting, and upset stomach.

Does Omnicef affect birth control?

Although the side effects of combining cefdinir (Omnicef) and birth control are not definite, it is best to use an extra contraception (condom or diaphragm) method during the cefdinir course. It would be best if you extended that time by a whole week of taking pills.

Aleksandra Zając, MD
Adults and adolestents >13 years
Community-acquired pneumonia (CAP)
💊 The patient should take 300 mg of Omnicef every 12 hours for 10 days.

For adult patients with creatinine clearance <30 mL/min/1.73 m², the dose of cefdinir should be 300 mg given once daily.
Always double-check the calculations, the dosing information and contraindications on the leaflet. Consult your health provider before administering any medication. This tool cannot replace real medical consultation.
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