Augmentin 400/57/5 mL Dosage Calculator
Calculate the estimated volume in mL per dose using the amoxicillin component of Augmentin 400 mg and clavulanate 57 mg per 5 mL suspension. This tool is designed for quick education and double checking, not for replacing a clinician’s prescription.
Expert guide to the Augmentin 400/57/5 mL dosage calculator
An Augmentin 400/57/5 mL dosage calculator helps convert a weight based prescription into a liquid volume that parents, pharmacists, nurses, and clinicians can measure more easily. The name of this product matters. Augmentin is a combination antibiotic made of amoxicillin plus clavulanate. When a label says 400/57 per 5 mL, it means each 5 mL contains 400 mg of amoxicillin and 57 mg of clavulanate. Because amoxicillin is usually the part used to set pediatric dosing, most calculations begin with a prescribed amoxicillin target in mg/kg/day, then convert that amount to mL based on the liquid concentration.
The reason a calculator is useful is simple. Even experienced caregivers can make mistakes when converting mg to mL, especially when several Augmentin suspensions exist. A child may receive the wrong amount if someone assumes all formulations have the same concentration. They do not. The 400/57 per 5 mL suspension is more concentrated in amoxicillin than the older 125/31.25 per 5 mL product, and it also has a different amoxicillin to clavulanate ratio. That difference affects both dosing accuracy and stomach tolerance.
How the calculator works
This calculator uses the amoxicillin concentration of the 400/57 suspension, which is 80 mg of amoxicillin per mL. If your prescriber chooses a dose such as 25 mg/kg/day or 45 mg/kg/day, the tool multiplies the child’s weight in kilograms by that daily target. It then divides the total daily amoxicillin dose by 80 mg per mL to convert the number into daily milliliters. Last, it divides by the number of daily doses, usually two for every 12 hours.
- Convert pounds to kilograms if needed.
- Multiply weight in kg by target mg/kg/day.
- Divide by 80 mg/mL to get total mL per day.
- Divide by the number of doses per day to get mL per dose.
Example: if a child weighs 20 kg and the chosen target is 45 mg/kg/day, the total amoxicillin per day is 900 mg. Since the suspension contains 80 mg/mL, the daily volume is 11.25 mL. If the medication is given twice daily, the dose is 5.625 mL every 12 hours, often rounded carefully according to the prescriber, pharmacy label, and oral syringe available.
Why the 400/57 concentration is commonly used
The 400/57 per 5 mL strength is widely used because it allows a meaningful amount of amoxicillin to be delivered without pushing clavulanate too high. Clavulanate helps block certain bacterial resistance mechanisms, but it is also the ingredient more commonly associated with diarrhea and stomach upset. A formulation with a better amoxicillin to clavulanate balance can be more comfortable for children while still providing the desired antibacterial coverage when a clinician decides Augmentin is appropriate.
This is also why formulations should never be swapped by volume alone. Five milliliters of one Augmentin liquid does not necessarily equal five milliliters of another. If the bottle changes, the mL dose may also change even when the amoxicillin target in mg stays the same.
Concentration comparison table
| Augmentin suspension strength | Amoxicillin per 5 mL | Clavulanate per 5 mL | Amoxicillin per mL | Clavulanate per mL |
|---|---|---|---|---|
| 125 mg / 31.25 mg per 5 mL | 125 mg | 31.25 mg | 25 mg/mL | 6.25 mg/mL |
| 200 mg / 28.5 mg per 5 mL | 200 mg | 28.5 mg | 40 mg/mL | 5.7 mg/mL |
| 400 mg / 57 mg per 5 mL | 400 mg | 57 mg | 80 mg/mL | 11.4 mg/mL |
| 600 mg / 42.9 mg per 5 mL | 600 mg | 42.9 mg | 120 mg/mL | 8.58 mg/mL |
Common pediatric dosing patterns
The exact prescribed target depends on the infection, the child’s age, local resistance patterns, kidney function, and the clinician’s judgment. In many pediatric settings, the 400/57 product is often used with every 12 hour dosing. Two common educational reference points are 25 mg/kg/day and 45 mg/kg/day, expressed as the amoxicillin component. The lower figure may be used for selected mild to moderate infections, while the higher figure may be chosen when stronger coverage is desired. However, the right prescription is ultimately a patient specific decision, not a calculator decision.
- Double check whether the prescription is written in mg of amoxicillin or in mL.
- Confirm the bottle says 400 mg and 57 mg per 5 mL before measuring.
- Use an oral syringe, not a kitchen spoon.
- Shake the suspension well each time before dosing.
- Give doses at evenly spaced times when possible.
Weight based sample dosing table for Augmentin 400/57 per 5 mL
| Weight | 25 mg/kg/day, 2 doses/day | 45 mg/kg/day, 2 doses/day | Total daily volume at 45 mg/kg/day |
|---|---|---|---|
| 10 kg | 1.6 mL per dose | 2.8 mL per dose | 5.6 mL/day |
| 15 kg | 2.3 mL per dose | 4.2 mL per dose | 8.4 mL/day |
| 20 kg | 3.1 mL per dose | 5.6 mL per dose | 11.3 mL/day |
| 25 kg | 3.9 mL per dose | 7.0 mL per dose | 14.1 mL/day |
| 30 kg | 4.7 mL per dose | 8.4 mL per dose | 16.9 mL/day |
Understanding the statistics behind the label
The most important statistics on the bottle are the concentrations. In the 400/57 product, every 1 mL contains 80 mg of amoxicillin and 11.4 mg of clavulanate. If you know those two numbers, you can estimate both the therapeutic amoxicillin amount and the clavulanate exposure. That matters because children who are prone to loose stools or stomach upset may react more to the clavulanate portion than to amoxicillin itself. The 400/57 formulation gives a higher amoxicillin concentration than older suspensions, which can keep the measured volume smaller and often make administration easier.
Another practical statistic is treatment supply. Parents frequently run short because they only calculate a single dose and forget to multiply by the full number of days. A 20 kg child receiving about 5.6 mL twice daily for 10 days needs about 112.5 mL total, not just a small partial bottle. A good calculator estimates the total volume required across the entire course, which helps avoid missed doses at the end of treatment.
What to do before giving each dose
- Read the pharmacy label and verify the concentration.
- Shake the bottle well until the liquid looks uniformly mixed.
- Draw up the exact amount in an oral syringe marked in 0.1 mL or 0.2 mL increments.
- Give with food if recommended, since this may improve stomach tolerance for some children.
- Store and discard according to the pharmacy instructions and expiration date.
When a calculator is helpful, and when it is not enough
A calculator is very helpful when you already know the intended amoxicillin target and need a clean conversion to mL. It is also useful for checking whether a written dose seems sensible for the child’s weight. For example, if a prescription appears to demand an unusually large volume for a small child, the calculator may alert you to a possible concentration mismatch.
Still, a calculator is not enough when there are clinical complications. Infants, children with kidney impairment, children with a history of severe allergy to penicillin class antibiotics, or those with repeated vomiting need individualized medical guidance. Likewise, if the child weighs more than 40 kg, many clinicians consider tablet or adult style dosing strategies rather than pediatric liquid calculations alone.
High value safety checks
- If the child develops hives, facial swelling, wheezing, or trouble breathing, seek urgent medical help.
- If vomiting prevents the child from keeping medicine down, call the prescriber for guidance.
- If severe diarrhea, dehydration, or unusual rash develops, ask the clinician or pharmacist what to do next.
- If symptoms are worsening after starting treatment, do not rely on the calculator to solve the problem. Reassessment may be needed.
Authoritative sources worth reviewing
For patient level medication information, review MedlinePlus drug information on amoxicillin and clavulanate. For national guidance on appropriate antibiotic use, see the CDC antibiotic use resources. For official product labeling and regulatory information, the U.S. Food and Drug Administration is also a reliable starting point.
Frequently asked practical questions
Is 400/57 per 5 mL the same as any other Augmentin liquid?
No. The amount of amoxicillin and clavulanate per mL changes by formulation. That means the volume per dose can change as well.
Can I round to the nearest teaspoon?
That is not ideal. Teaspoons are too imprecise for pediatric antibiotics. Use an oral syringe and follow the pharmacy label.
Should the dose be based on total body weight?
Most pediatric liquid antibiotic dosing references use weight in kilograms, but the final decision belongs to the prescribing clinician, especially in complex medical situations.
Why does the calculator mention clavulanate if dosing is based on amoxicillin?
Because clavulanate contributes to the combination product’s activity and side effect profile. Knowing the approximate clavulanate exposure helps explain why different formulations are not interchangeable.
Bottom line
The Augmentin 400/57/5 mL dosage calculator is best used as a precise conversion tool. It helps turn a weight based amoxicillin prescription into a practical mL dose, estimates the amount given per dose, and calculates how much medication may be needed for the full treatment course. Its real strength is reducing conversion errors, especially when caregivers are working with one of several similarly named Augmentin liquids. Even so, it should support, not replace, the instructions of a physician, nurse practitioner, physician assistant, or pharmacist. If the prescription, bottle strength, or child’s condition seems unclear, stop and verify before giving the medicine.