Calculate safe acetaminophen dosage based on weight
lbs
kgs
160 mg per 5 mL (Infant/Children's Liquid)
Recommended Dosage
Amount in mL
—
Dose in mg
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*This calculation is based on the standard 15 mg/kg dosage. Always consult your pediatrician before administering medication. Do not exceed 5 doses in 24 hours. Use only the dosing device that came with the product.
Understanding Infant Tylenol Dosage
Administering the correct amount of acetaminophen (Tylenol) to an infant is critical for safety and effectiveness. Medical professionals determine the correct dose based on the child's weight rather than their age, as babies of the same age can vary significantly in size.
How the Calculation Works
The standard safe dosage for pediatric acetaminophen is approximately 10 to 15 milligrams (mg) for every 1 kilogram (kg) of the child's body weight. This calculator uses the 15 mg/kg standard, which is common for effectively reducing fever and pain in infants and children.
The formula used by this calculator is:
Step 1: Convert weight to kilograms (if entered in pounds). Weight in lbs / 2.2046 = Weight in kg.
Step 2: Calculate mg dose. Weight in kg × 15 mg = Total mg dose.
Step 3: Convert mg to mL. (Total mg dose / 160 mg) × 5 mL = Dose in mL.
Common Dosage Examples
Weight (lbs)
Weight (kg)
Recommended mL (160mg/5mL)
6 – 11 lbs
2.7 – 5.0 kg
1.25 mL
12 – 17 lbs
5.4 – 7.7 kg
2.5 mL
18 – 23 lbs
8.2 – 10.4 kg
3.75 mL
24 – 35 lbs
10.9 – 15.9 kg
5 mL
Important Safety Guidelines
Wait Time: Wait at least 4 to 6 hours between every dose.
Daily Maximum: Never give more than 5 doses in any 24-hour period.
Use Provided Tools: Always use the oral syringe or dropper that came with the specific bottle of Tylenol you purchased. Kitchen spoons are not accurate for measuring medicine.
Check Concentrations: While most infant and children's Tylenol in the US is now the same concentration (160mg/5mL), always verify the label on your bottle before calculating.
When to Call the Doctor: If your infant is under 3 months old and has a fever, call your pediatrician immediately before giving any medication.
function calculateTylenolDose() {
var weightInput = document.getElementById("babyWeight").value;
var unit = document.getElementById("weightUnit").value;
var resultDiv = document.getElementById("tylenolResult");
var mlOutput = document.getElementById("mlOutput");
var mgOutput = document.getElementById("mgOutput");
var weightNum = parseFloat(weightInput);
if (isNaN(weightNum) || weightNum <= 0) {
alert("Please enter a valid weight for your child.");
return;
}
var weightInKg;
if (unit === "lb") {
weightInKg = weightNum / 2.20462;
} else {
weightInKg = weightNum;
}
// Standard dosage is 15mg per kg
var dosageMg = weightInKg * 15;
// Standard concentration is 160mg per 5mL
// So 1mL = 32mg
var dosageMl = dosageMg / 32;
// Formatting results
// We round mL to the nearest 0.1 for practical measurement,
// but often syringes have 1.25, 2.5, 3.75 marks.
// For safety, we round to 2 decimals for precision.
var finalMl = Math.round(dosageMl * 100) / 100;
var finalMg = Math.round(dosageMg * 10) / 10;
mlOutput.innerHTML = finalMl + " mL";
mgOutput.innerHTML = finalMg + " mg";
resultDiv.style.display = "block";
// Smooth scroll to result
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}