Antibiotic Dose by Weight Calculator

Enter a weight and select a reference regimen to illustrate its weight-based daily and per-administration amounts. A prescriber must select and verify the actual regimen.

Use the Antibiotic Dose by Weight Calculator

Patient Details

Educational arithmetic only — not a prescription or a medication-safety check. The tool does not collect age, indication, allergies, pregnancy, formulation, kidney/liver function, interactions, or local resistance. A licensed prescriber and pharmacist must select and verify the complete regimen before any antibiotic is administered.

Enter weight and select an antibiotic to calculate the dose.

Summary

Enter a weight and select a reference regimen to illustrate its weight-based daily and per-administration amounts. A prescriber must select and verify the actual regimen.

How it works

  1. Enter the patient weight in kilograms or pounds — the tool converts automatically.
  2. Select the antibiotic from the dropdown list.
  3. Choose the indication or dosing tier if multiple options exist.
  4. The calculator applies the selected reference mg/kg/day value and divides by its configured frequency.
  5. Results show total daily dose, dose per administration, and the patient-specific configured mg/kg range.
  6. A notice appears when the arithmetic result is limited by the configured absolute daily cap.

Use cases

  • Illustrate amoxicillin mg/kg arithmetic for a teaching example.
  • Explore how a multi-day azithromycin reference schedule changes after day one.
  • Compare the displayed trimethoprim-based arithmetic with a prescribed regimen.
  • Compare weight-based arithmetic across the listed educational reference regimens.
  • See how an absolute daily cap changes a weight-based calculation.
  • Compare dosing across multiple antibiotics for the same patient weight.
  • Support clinical education and pharmacology learning.
  • Practice converting between mg/kg/day and mg per administration.

Frequently Asked Questions

Last updated: 2026-09-13 · Reviewed by Nham Vu