Tamiflu Pediatric Dosing Calculator
Use this Tamiflu pediatric dose calculator to match the child's weight band to an oseltamivir treatment or prevention plan, then convert it into 6 mg/mL liquid mL or capsule strengths.
Tamiflu (oseltamivir) dosage chart by weight for children 1 to 12 years (6 mg/mL)
For children 1 to 12 years, the Tamiflu label gives a fixed dose by weight band: the same mg for treatment (twice a day for 5 days) and prevention (once a day). Use the column that matches the prescription; start treatment as soon as possible after flu symptoms begin.
- Give the mL on your pharmacy label. If it differs from this chart, call the pharmacist; don't change the dose yourself.
- Prevention is once a day, not twice. Check which one your child was prescribed.
- These mL are only for 6 mg/mL suspension. If your bottle says 12 mg/mL or was made by the pharmacy, use the mL on your label. Capsules come as 30, 45 and 75 mg; 60 mg is two 30 mg capsules.
| Weight (kg) | Weight (lb) | Treatment: twice a day for 5 daysmL of 6 mg/mL suspension per dose (mg it contains) | Prevention: once a day (7-10 days)mL of 6 mg/mL suspension per dose (mg it contains) |
|---|---|---|---|
| 15 kg or less | 33 lb or less | 5 mL (30 mg) | 5 mL (30 mg) |
| over 15 to 23 kg | over 33 to 51 lb | 7.5 mL (45 mg) | 7.5 mL (45 mg) |
| over 23 to 40 kg | over 51 to 88 lb | 10 mL (60 mg) | 10 mL (60 mg) |
| over 40 kg | over 88 lb | 12.5 mL (75 mg) | 12.5 mL (75 mg) |
- Treatment: the band dose twice a day for 5 days (label).
- Prevention after exposure: the same band dose ONCE a day, for 10 days (label) or 7 days after the last exposure (CDC), only if prescribed.
- 13 years and older: 75 mg (12.5 mL or one 75 mg capsule) at any weight, twice a day for treatment or once a day for prevention (label).
- Under 1 year: 3 mg/kg per dose; see the under-1 chart on pedscalc.com/oseltamivir.
- Kidney disease: the dose is often lower; follow the prescription.
- Start treatment as soon as possible after symptoms begin. Giving it with food can ease stomach upset.
- Use the dosing syringe from the pharmacy.
Tamiflu (oseltamivir) dose for babies under 1 year (3 mg/kg, 6 mg/mL)
For babies under 1 year born at term: 3 mg/kg per dose at any weight. Treatment is twice a day for 5 days; prevention is once a day and only from 3 months (CDC). Use the column that matches the prescription.
- Give the mL on your pharmacy label. If it differs from this chart, call the pharmacist; don't change the dose yourself.
- Babies born early (preterm) need lower doses based on age since conception: ask the NICU or pediatrician.
- These mL are only for 6 mg/mL suspension. If your bottle says 12 mg/mL or was made by the pharmacy, use the mL on your label.
| Weight (kg) | Weight (lb) | Treatment: 3 mg/kg twice a daymL of 6 mg/mL suspension per dose (mg it contains) | Prevention (3 months+): 3 mg/kg once a day, 7 daysmL of 6 mg/mL suspension per dose (mg it contains) |
|---|---|---|---|
| 4 | 9 | 2 mL (12 mg) | 2 mL (12 mg) |
| 5 | 11 | 2.5 mL (15 mg) | 2.5 mL (15 mg) |
| 6 | 13 | 3 mL (18 mg) | 3 mL (18 mg) |
| 7 | 15 | 3.5 mL (21 mg) | 3.5 mL (21 mg) |
| 8 | 18 | 4 mL (24 mg) | 4 mL (24 mg) |
| 9 | 20 | 4.5 mL (27 mg) | 4.5 mL (27 mg) |
| 10 | 22 | 5 mL (30 mg) | 5 mL (30 mg) |
| 11 | 24 | 5.5 mL (33 mg) | 5.5 mL (33 mg) |
| 12 | 26 | 6 mL (36 mg) | 6 mL (36 mg) |
- Treatment: 3 mg/kg per dose twice a day for 5 days (label from 2 weeks; CDC also uses 3 mg/kg for term newborns under 2 weeks, off-label).
- Prevention: 3 mg/kg once a day for 7 days after the last exposure, only for babies 3 months and older and only if prescribed (CDC; the label does not cover prevention under 1 year).
- 9 to 11 months: some prescribers use 3.5 mg/kg per dose (AAP, noted by CDC), so your label may show a little more than this chart.
- Prevention is not recommended under 3 months except in special situations (CDC).
- Kidney disease: the dose is often lower; follow the prescription.
- mL is rounded to 0.1 mL under 5 mL and to 0.5 mL from 5 mL; use the dosing syringe from the pharmacy.
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dose calculator basics
Oseltamivir pediatric dose calculator details
Use this Oseltamivir calculator as the fast parent page for weight-based dose checks, mL conversion, common strengths, and the practical safety steps that generic calculator sites often skip.
Formula
mL per dose = (child weight in kg x prescribed mg/kg/day / doses per day) / medication concentration in mg per mL.
Worked example
For a 20 kg child using 6 mg/kg/day divided 2 times daily with 6 mg/1 mL, calculate the daily mg target, divide by the schedule, then convert that mg amount into mL for the selected product.
Safety checks before using the result
- Use the exact product strength in hand before measuring the dose.
- Confirm maximum dose, age limits, and indication-specific cautions when they apply.
- Escalate urgent symptoms or medication reactions instead of repeating doses from calculator output alone.
Practical dosing guide
Before you measure the dose
Use this page to match the influenza treatment or prevention plan to the child's weight, the liquid or capsule strength in hand, and the timing since symptoms started.
- 6 mg/mL Tamiflu suspension
- The standard liquid is 6 mg/mL, so converting the prescribed dose into exact mL is usually the main reason families search for a Tamiflu calculator.
- Flu treatment
- Most pediatric treatment plans are twice daily for 5 days, with the biggest upside when treatment starts within the first 48 hours of symptoms.
- Post-exposure prevention
- Prevention plans are different from treatment plans and are often once daily.
Oseltamivir pediatric medication summary
Oseltamivir (Tamiflu) is used for pediatric influenza treatment and selected prevention plans. Use the Tamiflu pediatric dosing calculator to convert weight-based dosing into exact mL for the 6 mg/mL suspension or into the right capsule strength.
Start as early as possible—ideally within 48 hours
Weight‑based dosing via 6 mg/mL liquid or weight‑banded capsules
Oseltamivir indications and common pediatric uses
Oseltamivir is the frontline antiviral for pediatric influenza when treatment timing and dosing are executed correctly.
Treatment of suspected or confirmed influenza A/B
Treatment of suspected or confirmed influenza A/B: Therapy supports complication reduction; it does not replace respiratory distress or dehydration escalation pathways.
Post-exposure prophylaxis during high-risk household or institutional exposure
Post-exposure prophylaxis during high-risk household or institutional exposure: Prophylaxis should not replace vaccination strategy and source-control measures.
Protocolized chemoprophylaxis in neonatal/critical-care influenza outbreaks
Protocolized chemoprophylaxis in neonatal/critical-care influenza outbreaks: Use is context-specific and should not be generalized to routine outpatient care.
How to give Oseltamivir
- Practical pediatric administration guidance for treatment and prophylaxis workflows.
- Shake suspension for at least 10 seconds, measure exact mL dose with oral syringe, and administer slowly toward the inner cheek. Capsules can be opened and mixed with a small amount of sweetened food when swallowing is not possible; give immediately and complete the full portion.
Oseltamivir side effects, contraindications, and interactions
Oseltamivir is usually tolerated well, with nausea and vomiting as the most common side effects. Most issues are manageable when dosing, hydration, and follow-up are structured.
Common side effects
- Use food support and hydration to reduce GI side effects and preserve course completion.
- Do not continue unsupervised if vomiting prevents fluids or medication tolerance.
- Treat abrupt neurobehavioral changes or severe rash as urgent stop-and-evaluate events.
Safety checks
- Renal impairment: Reduced clearance increases exposure and GI side effects.
- Hereditary fructose intolerance: Commercial suspension contains sorbitol.
- Hallucinations, confusion, or self-harm behavior: Possible neuropsychiatric reaction.
- Angioedema or difficulty breathing: Possible hypersensitivity reaction.
Drug interactions
- Review the full medication list with a clinician or pharmacist before combining therapies.
Oseltamivir mechanism and clinical pearls
Oseltamivir is converted to oseltamivir carboxylate, which inhibits influenza neuraminidase and slows release of newly formed virions from infected respiratory cells. Mechanism benefit is time-sensitive: earlier treatment limits viral spread and can reduce symptom duration and complication risk, especially in high-risk children.
Document symptom-onset time and start therapy promptly when indicated; delay erodes antiviral benefit.
Use oral syringes and recorded mL dosing for liquid formulations; avoid household spoon estimates.
Give with food/snack when nausea appears and pair with hydration strategy so treatment completion remains feasible.
Check kidney-risk context before prescribing and adjust regimen in reduced renal function to avoid accumulation and intolerance.
Frequently asked questions about Oseltamivir
As soon as possible—ideally within 48 hours of symptom onset. Starting early helps shorten illness and may reduce complications, especially in children at higher risk.
Yes. Oseltamivir is active against both influenza A and B, but it only helps with true influenza, not common colds or other viruses.
Yes. Give the dose with food to reduce nausea. If your child vomits immediately after the dose, call your clinician before repeating.
In some situations, clinicians prescribe post‑exposure prophylaxis for close contacts at higher risk. This is usually once daily for about 10 days—ask your clinician if it’s appropriate.
No. Antivirals are treatments; vaccination remains the best protection against influenza. Antivirals can also interfere with the live nasal spray vaccine (LAIV) if given too close together—your clinician will advise on timing.
Tamiflu dosing is weight-based. Use the calculator to convert the prescribed oseltamivir plan into exact mL for the 6 mg/mL suspension or into the right capsule strength, then confirm whether the schedule is for treatment or prevention.
The standard oral suspension is 6 mg/mL. The calculator converts the prescribed oseltamivir plan into the exact mL dose for this strength.
Sources reviewed for Oseltamivir
cdc-influenza-antivirals-2024
idsa-influenza-2018
Influenza Antiviral Medications: Summary for Clinicians
Centers for Disease Control and Prevention
SourceClinical Practice Guidelines for Seasonal Influenza
Infectious Diseases Society of America
SourceCDC – Antiviral Medications: Summary for Clinicians
CDC
SourceOseltamivir for influenza
Medicines for Children
Source