About ToolSite

Pediatric medication dosing is not intuitive. Children are not small adults — their drug metabolism, renal clearance, and body composition change rapidly during the first decade of life. A flat dose based on age is inadequate; weight-based dosing in mg/kg is the clinical standard, and doing that math correctly every time is where errors happen.

This site exists to make that calculation fast, accurate, and accessible. Every calculator applies the published guideline dose rate for the drug and indication, caps doses at the published maximum, and converts the mg dose to mL based on the suspension concentration you select. The math a clinical pharmacist would do in 60 seconds is done in 5.

We cover the 13 most commonly prescribed pediatric drugs in outpatient practice: antibiotics (Augmentin, cefdinir, azithromycin, cephalexin, Bactrim, clindamycin, cefuroxime), corticosteroids (prednisolone, dexamethasone), an antiemetic (ondansetron), and acid-suppressants (omeprazole, famotidine, metronidazole). These cover the bulk of weight-based dosing questions that come up at a pediatric outpatient visit.

Every dose rate in our calculators comes from a named, authoritative clinical source. We don't invent or approximate dose ranges. The primary references we use:

• AAP Red Book — American Academy of Pediatrics — antibiotic dosing and infectious disease
• NAEPP — National Asthma Education and Prevention Program — corticosteroid dosing for asthma
• KDIGO — Kidney Disease: Improving Global Outcomes — nephrotic syndrome steroid protocols
• IDSA — Infectious Diseases Society of America — antibiotic selection and dosing guidelines
• NASPGHAN — Pediatric gastroenterology guidelines — omeprazole and famotidine dosing
• Lexicomp Pediatric — Drug information database used by hospital pharmacists

Sources are listed on every individual calculator page. When a guideline is updated, we review and update the relevant calculators. If you identify a discrepancy with a current guideline, use the contact form below.

Each calculator is built from the ground up for its specific drug and indication. The process:

1. Step 1. Source the dose rate and maximum dose from the primary clinical guideline (AAP, NAEPP, KDIGO, IDSA, or NASPGHAN).
2. Step 2. Cross-reference with Lexicomp Pediatric Drug Information for available formulations and concentrations.
3. Step 3. Implement the calculation with weight input, indication selection, concentration selection, and max-dose cap.
4. Step 4. Test the calculator against 5+ manual calculations across the weight range (5 kg to 40 kg) and at the maximum dose boundary.
5. Step 5. List the specific guideline sources on the calculator page so users can verify independently.
6. Step 6. Review when relevant guidelines update.

Important: These calculators are educational reference tools. They do not replace clinical judgment, prescriber guidance, or institutional dosing protocols. A dispensed prescription should always be verified against the patient's medical record and the clinician's order.

Our calculators are accurate for children in the standard weight range (typically 1–80 kg) receiving standard indications for each drug. They are not designed for:

• Neonates or premature infants (use NeoFax or consult a neonatologist)
• Children with significant renal or hepatic impairment (dosing may need adjustment)
• Off-label indications not listed in the indication dropdown
• IV or IM dosing — all calculators are for oral administration
• Replacing a pharmacist, prescriber, or clinical pharmacology consultation