How do I calculate the volume of Augmentin (amoxicillin-clavulanate) 467 mg/5ml needed to achieve a dose of 540mg for a 20-month-old, 12 kg child?

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Last updated: January 20, 2026View editorial policy

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Calculating Augmentin Volume for Dose Adjustment

To calculate the volume needed when your concentration is 467 mg/5mL and you need 540 mg: multiply 540 mg by 5 mL, then divide by 467 mg, which equals 5.78 mL.

The Calculation Method

The formula is: (Desired dose in mg × Volume of available concentration) ÷ Concentration in mg = Volume to administer

  • For this specific case: (540 mg × 5 mL) ÷ 467 mg = 5.78 mL 1
  • This represents the volume needed to deliver the full 540 mg dose from your 467 mg/5mL suspension 1

Practical Considerations for Pediatric Dosing

For a 20-month-old child weighing 12 kg, the standard amoxicillin-clavulanate dosing is 40-45 mg/kg/day of the amoxicillin component divided every 12 hours, which would be 480-540 mg per day total, or 240-270 mg per dose twice daily 1, 2

  • The 467 mg/5mL concentration appears to be a high-dose formulation (approximately 400 mg/5mL of amoxicillin component) 1, 3
  • If the prescribed dose is 540 mg total daily (270 mg twice daily), you would administer approximately 2.89 mL per dose 1
  • If the prescribed dose is 540 mg per individual dose (which would be high for this weight), you would administer 5.78 mL per dose 1

Dosing Context for This Age and Weight

Standard dosing for community-acquired infections in children ≥3 months is 25-45 mg/kg/day of amoxicillin component every 12 hours 1

  • For a 12 kg child at 40 mg/kg/day: 480 mg/day total = 240 mg per dose twice daily 1
  • For a 12 kg child at 45 mg/kg/day: 540 mg/day total = 270 mg per dose twice daily 1, 2
  • High-dose formulations (90 mg/kg/day) are reserved for recurrent/persistent acute otitis media with resistant pathogens, which would be 1080 mg/day = 540 mg per dose twice daily 1, 4, 3

Verification Steps

  • Always confirm whether the 540 mg represents the total daily dose or the individual dose 1
  • Verify the prescription matches appropriate weight-based dosing for the indication 1, 2
  • Use an oral syringe for accurate measurement of the calculated volume 1
  • The twice-daily dosing regimen is preferred as it is associated with significantly less diarrhea compared to three-times-daily dosing 1, 5

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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