Safely determine the correct Advil (ibuprofen) dosage for adults and children based on their body weight using our expert-reviewed calculator and guide.
Advil Dosage Calculator (Weight-Based)
Enter weight in kilograms (kg).
Advil Tablets (200 mg)
Advil Liqui-Gels (200 mg each, total 400mg in pack – use for reference if needed, but calc uses per pill mg)
Advil Extra Strength (e.g., prescription strength, 600 mg)
Advil Maximum Strength (e.g., prescription strength, 800 mg)
Select the strength of the Advil product you are using. Note: Standard Advil is 200mg.
Every 4 hours
Every 6 hours
Every 8 hours
How often you plan to take the Advil.
Your Calculated Advil Dosage:
— mg
Single Dose: — mg
Max Daily Dose: — mg
Pills Per Dose: —
Formula Used:
The standard recommended dosage for ibuprofen (Advil) is typically 5-10 mg per kilogram of body weight per dose, not to exceed 40 mg per kilogram per day. We calculate the single dose within this range and the maximum daily limit.
What is Advil Dosage Calculation by Weight?
Calculating Advil dosage by weight is a crucial method for ensuring safe and effective pain relief, particularly for children and individuals with varying body sizes. Advil, containing the active ingredient ibuprofen, is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce fever and treat pain and inflammation. Because the body's metabolism and response to medication can vary significantly with weight, a weight-based dosage calculation provides a more personalized and accurate approach than relying on a one-size-fits-all recommendation. This method helps prevent underdosing (which can lead to ineffective treatment) and overdosing (which can increase the risk of side effects).
Who should use it?
This method is especially recommended for:
Children: Pediatric dosages are almost always calculated based on weight to ensure safety and efficacy.
Adults with significantly low or high body weight: Standard adult doses might not be optimal for individuals at the extremes of the weight spectrum.
Individuals following specific medical advice: Healthcare providers may recommend precise weight-based dosing.
Common Misconceptions:
"Adult dose is always X mg": While standard adult doses exist (e.g., 200-400 mg every 4-6 hours), they are often based on an average adult weight. For individuals significantly lighter or heavier, this may not be the most accurate dose.
"More weight means proportionally more medicine": Dosage calculation isn't always linear. There are maximum safe daily limits that must be respected regardless of weight.
"Any Advil will do": Different formulations (tablets, liquid gels, prescription strengths) have different concentrations, and the calculation needs to consider the specific product's milligram (mg) strength.
Advil Dosage by Weight Formula and Mathematical Explanation
The calculation of Advil (ibuprofen) dosage by weight relies on established pediatric and general guidelines. The most common recommendation is a range of 5 mg to 10 mg of ibuprofen per kilogram (kg) of body weight for each individual dose. Crucially, there's a maximum daily limit that should not be exceeded to prevent toxicity.
Step-by-Step Derivation:
Determine Single Dose Range: Calculate the lower and upper bounds for a single dose based on the patient's weight.
Lower Bound (mg) = Body Weight (kg) × 5 mg/kg
Upper Bound (mg) = Body Weight (kg) × 10 mg/kg
The chosen single dose should fall within this calculated range. For most non-prescription uses, the target is often around 7.5 mg/kg or the closest appropriate dose.
Determine Maximum Daily Dose: Calculate the absolute maximum amount of ibuprofen that can be safely administered within a 24-hour period.
Maximum Daily Dose (mg) = Body Weight (kg) × 40 mg/kg
This limit is critical and must not be surpassed, regardless of the patient's weight or the severity of symptoms.
Calculate Number of Pills: Divide the calculated single dose (in mg) by the strength of the Advil formulation being used (e.g., 200 mg per tablet) to determine the number of pills required for that dose.
Pills per Dose = Single Dose (mg) / Strength per Pill (mg)
Round this number to the nearest practical or whole pill, considering the recommended single dose range.
Check Against Frequency Limits: Ensure that taking the calculated single dose at the specified frequency does not exceed the Maximum Daily Dose.
Variable Explanations:
Understanding the variables involved is key to accurate calculation:
Variable
Meaning
Unit
Typical Range/Considerations
Body Weight
The total mass of the individual.
Kilograms (kg)
Essential for personalized dosing. Use accurate measurements.
Dosage Strength
The amount of active ingredient (ibuprofen) in one unit (e.g., tablet, gelcap) of the medication.
Milligrams (mg)
Commonly 200 mg (standard Advil), but can be higher (e.g., 400 mg, 600 mg, 800 mg) for prescription or specific formulations.
Frequency of Dose
How often the medication is taken within a 24-hour period.
Hours (e.g., 4, 6, 8)
Determines how many doses contribute to the maximum daily total. Standard NSAID guidelines often suggest every 4-8 hours.
Single Dose Recommendation
The calculated amount of ibuprofen for one administration.
Milligrams (mg)
Typically between 5-10 mg/kg.
Maximum Daily Dose
The highest total amount of ibuprofen considered safe to take in a 24-hour period.
Milligrams (mg)
Generally limited to 40 mg/kg per day, with an absolute maximum often cited around 2400-3200 mg for adults depending on medical supervision.
Pills Per Dose
The number of medication units (e.g., tablets) to take for a single dose.
Count (e.g., 1, 1.5, 2)
Must be practical (e.g., usually whole or half pills).
Practical Examples (Real-World Use Cases)
Let's illustrate how to calculate Advil dosage with two practical examples:
Example 1: Child with Fever
Scenario: A child weighing 25 kg has a fever and needs Advil. The available medication is standard Advil 200 mg tablets. The recommended frequency is every 6 hours.
Calculation Steps:
Weight: 25 kg
Dosage Strength: 200 mg per tablet
Frequency: Every 6 hours
Single Dose Range:
Low end: 25 kg * 5 mg/kg = 125 mg
High end: 25 kg * 10 mg/kg = 250 mg
We aim for a dose within 125-250 mg. Let's target the middle, around 7.5 mg/kg: 25 kg * 7.5 mg/kg = 187.5 mg. The closest practical dose from the range is 200 mg.
Pills per Dose: 200 mg (calculated single dose) / 200 mg (per tablet) = 1 pill.
Maximum Daily Dose: 25 kg * 40 mg/kg = 1000 mg.
Check Frequency: If 200 mg is given every 6 hours, that's 4 doses in 24 hours. Total daily intake = 200 mg/dose * 4 doses = 800 mg. This is below the 1000 mg maximum daily limit, so it's safe.
Result: Administer 1 tablet (200 mg) of Advil every 6 hours. The total maximum daily dose should not exceed 1000 mg (which would be 5 tablets).
Example 2: Adult with Moderate Pain
Scenario: An adult weighing 60 kg is experiencing moderate pain. They have Advil Liqui-Gels, which contain 200 mg of ibuprofen each. The doctor advised taking it every 8 hours if needed.
Calculation Steps:
Weight: 60 kg
Dosage Strength: 200 mg per Liqui-Gel
Frequency: Every 8 hours
Single Dose Range:
Low end: 60 kg * 5 mg/kg = 300 mg
High end: 60 kg * 10 mg/kg = 600 mg
A standard adult dose of 400 mg falls nicely within this range.
Pills per Dose: 400 mg (chosen single dose) / 200 mg (per Liqui-Gel) = 2 Liqui-Gels.
Maximum Daily Dose: 60 kg * 40 mg/kg = 2400 mg.
Check Frequency: If 400 mg is given every 8 hours, that's 3 doses in 24 hours. Total daily intake = 400 mg/dose * 3 doses = 1200 mg. This is well below the 2400 mg maximum daily limit, so it's safe.
Result: Take 2 Liqui-Gels (400 mg total) every 8 hours as needed. The total maximum daily dose should not exceed 2400 mg (which would be 12 Liqui-Gels).
How to Use This Advil Dosage Calculator
Our Advil Dosage Calculator is designed for simplicity and accuracy, helping you quickly determine an appropriate ibuprofen dosage based on weight. Follow these steps for best results:
Enter Body Weight: Input the individual's weight in kilograms (kg) into the "Body Weight" field. Ensure accuracy for the most precise calculation. If you only know the weight in pounds (lbs), convert it to kg by dividing by 2.205 (e.g., 150 lbs / 2.205 = 68 kg).
Select Advil Strength: Choose the specific Advil product you have from the "Advil Strength" dropdown menu. Common options include 200 mg tablets. If you have a different strength, select the closest or consult the packaging.
Choose Frequency: Select how often you intend to administer the dose (e.g., "Every 4 hours," "Every 6 hours," "Every 8 hours") from the "Frequency of Dose" dropdown.
View Results: Once you've entered the information, the calculator will instantly display:
Primary Result (Highlighted): The recommended single dose in milligrams (mg).
Intermediate Values: Your calculated Single Dose (mg), Maximum Daily Dose (mg), and the number of Pills per Dose required.
Formula Explanation: A brief reminder of the calculation logic used.
How to Read Results: The primary result is your target dose for each administration. The "Pills Per Dose" indicates how many units of your chosen Advil strength you should take. Always ensure your total daily intake stays below the calculated "Maximum Daily Dose."
Decision-Making Guidance: Use the calculated dose as a guide. Always consult a healthcare professional for children under 2 years old, or if you have any concerns about dosage, potential drug interactions, or underlying health conditions. This calculator is a tool, not a substitute for professional medical advice.
Key Factors That Affect Advil Dosage Results
While weight is the primary factor, several other elements can influence the appropriate Advil dosage and its effectiveness. Understanding these factors ensures a more holistic approach to pain management:
Kidney Function: Ibuprofen is metabolized and excreted by the kidneys. Individuals with impaired kidney function may require lower doses or less frequent administration to prevent accumulation and potential kidney damage. Always consult a doctor if kidney issues are present.
Liver Function: Similar to the kidneys, the liver plays a role in drug metabolism. Significant liver disease might necessitate dosage adjustments.
Age: While we focus on weight, age is also critical, especially for infants and the elderly. Infants under 6 months generally should not receive ibuprofen unless specifically directed by a pediatrician. The elderly may be more susceptible to side effects like gastrointestinal bleeding.
Other Medications: Ibuprofen can interact with other drugs, including blood thinners (e.g., warfarin), other NSAIDs, aspirin, certain antidepressants (SSRIs), and diuretics. These interactions can increase the risk of side effects, particularly bleeding or kidney problems. Always inform your doctor about all medications you are taking.
Hydration Status: Dehydration can concentrate medications in the body and potentially impact kidney function, increasing the risk of adverse effects from NSAIDs like Advil. Staying adequately hydrated is important.
Severity and Type of Condition: While dosage is primarily weight-based, the reason for taking Advil matters. Acute pain or high fever might warrant a dose at the higher end of the recommended range (10 mg/kg), while mild aches could be managed with a lower dose (5 mg/kg). However, never exceed the maximum daily limit.
Stomach Sensitivity: NSAIDs like Advil can irritate the stomach lining. Taking the medication with food or milk can help minimize this risk, especially for individuals prone to ulcers or heartburn. Dosage adjustments might be considered if significant gastrointestinal upset occurs.
Frequently Asked Questions (FAQ)
Q1: What is the standard recommended dosage for Advil (ibuprofen) for adults?
For adults, the typical dose is 200 mg to 400 mg (1-2 standard tablets) every 4 to 6 hours as needed. However, our calculator can provide a more personalized dose based on weight, especially for adults who are significantly outside the average weight range. Always adhere to the maximum daily dose.
Q2: Can I give Advil to my baby?
Ibuprofen (Advil) is generally not recommended for infants under 6 months of age unless specifically advised by a pediatrician. For infants older than 6 months, dosage must be calculated strictly by weight using pediatric formulations and following medical guidance. Consult your doctor before administering any medication to an infant.
Q3: What happens if I take too much Advil?
Taking more Advil than recommended can lead to serious side effects, including stomach upset, ulcers, bleeding, kidney damage, liver problems, and an increased risk of heart attack or stroke. Always follow dosage instructions carefully and seek immediate medical attention if an overdose is suspected.
Q4: How many 200 mg Advil pills can I take in a day?
For adults, the maximum recommended daily dose of ibuprofen is typically 1200 mg (or 6 x 200 mg tablets) for over-the-counter use. Prescription strengths can go higher, up to 3200 mg per day under strict medical supervision. Our calculator helps determine the maximum daily dose based on weight (40 mg/kg). For a 70 kg adult, this would be 2800 mg. However, for OTC use, stick to the general adult maximum unless advised otherwise by a doctor.
Q5: Should I take Advil with food?
Yes, it is generally recommended to take Advil (ibuprofen) with food or milk to minimize the risk of stomach irritation, heartburn, or ulcers. If you have a sensitive stomach, this is particularly important.
Q6: What is the difference between Advil and other ibuprofen brands?
Advil is a brand name for ibuprofen. Other brands also contain ibuprofen as the active ingredient. The dosage calculations are the same for any medication containing ibuprofen, but you must always refer to the specific strength (mg per pill/dose) listed on the packaging of the product you are using.
Q7: My child weighs 15 kg. What is an appropriate Advil dose?
Using the 5-10 mg/kg guideline: A dose could range from 75 mg (15 kg * 5 mg/kg) to 150 mg (15 kg * 10 mg/kg). If using 200 mg tablets, you would likely administer half a tablet (100 mg), which falls within this range. The maximum daily dose would be 600 mg (15 kg * 40 mg/kg). Always consult a pediatrician for pediatric dosing.
Q8: Does this calculator provide prescription-strength Advil dosage?
This calculator provides dosage recommendations based on common guidelines (5-10 mg/kg per dose, max 40 mg/kg/day) suitable for over-the-counter strengths like 200mg. While the formula is applicable, prescription strengths (e.g., 600mg, 800mg) require specific medical direction. Always follow your doctor's prescription for higher strengths.
A tool to help identify potential risks when taking Advil with other medications (Note: This is a placeholder, actual link would go to an interaction checker tool).
var currentStrengthMg = 200; // Default to 200mg
function updateStrengthInfo() {
var selectElement = document.getElementById("dosageForm");
currentStrengthMg = parseInt(selectElement.value);
var strengthDisplay = document.querySelector('.input-group label[for="dosageForm"] + input[type="number"], .input-group label[for="dosageForm"] + select');
if (strengthDisplay) {
// The helper text might be the only place to show context if select is used
}
}
function validateInput(id, min, max, isRequired = true) {
var element = document.getElementById(id);
var errorElement = document.getElementById(id + "Error");
var value = parseFloat(element.value);
errorElement.textContent = ""; // Clear previous error
if (isRequired && (element.value === null || element.value === "")) {
errorElement.textContent = "This field is required.";
return false;
}
if (isNaN(value)) {
if(element.value !== "") { // Only show error if input is not empty but is NaN
errorElement.textContent = "Please enter a valid number.";
return false;
}
return true; // Allow empty if not required
}
if (value max) {
errorElement.textContent = "Value is too high.";
return false;
}
return true;
}
function calculateDosage() {
var weightKgInput = document.getElementById("weightKg");
var frequencySelect = document.getElementById("frequency");
var mainResultDiv = document.getElementById("mainResult");
var singleDoseDiv = document.querySelector(".intermediate-results #singleDose span");
var maxDailyDoseDiv = document.querySelector(".intermediate-results #maxDailyDose span");
var pillsPerDoseDiv = document.querySelector(".intermediate-results #pillsPerDose span");
// Clear previous results and errors
mainResultDiv.textContent = "– mg";
singleDoseDiv.textContent = "– mg";
maxDailyDoseDiv.textContent = "– mg";
pillsPerDoseDiv.textContent = "–";
document.getElementById("weightKgError").textContent = "";
document.getElementById("dosageFormError").textContent = "";
document.getElementById("frequencyError").textContent = "";
var isValid = true;
if (!validateInput("weightKg", 0, null)) isValid = false;
// No specific validation for dosageForm select other than it being present
// No specific validation for frequency select other than it being present
if (!isValid) {
return;
}
var weightKg = parseFloat(weightKgInput.value);
var frequency = parseInt(frequencySelect.value);
var strengthPerPill = currentStrengthMg; // Use the globally updated value
// Dosage calculation based on 5-10 mg/kg per dose
var minSingleDose = weightKg * 5;
var maxSingleDose = weightKg * 10;
var maxDailyDose = weightKg * 40;
// Aim for a middle-ground dose, e.g., 7.5 mg/kg, or the closest practical dose within the range
var targetSingleDose = weightKg * 7.5;
// Adjust targetSingleDose to be practical with available pill strength if needed, but prioritize range.
// For simplicity, we'll use the calculated target and then determine pills.
// Ensure single dose is within the 5-10 mg/kg range.
var finalSingleDose = Math.max(minSingleDose, Math.min(maxSingleDose, targetSingleDose));
// Ensure the dose calculated results in a whole or half pill if possible, or adjust slightly.
// For this calculator, we'll calculate the ideal mg dose first, then pills.
// If the finalSingleDose is very close to a standard pill, round to it.
// Example: If finalSingleDose is 190mg and strength is 200mg, use 200mg.
// Let's keep it simpler: calculate mg, then calculate pills.
var pillsPerDose = finalSingleDose / strengthPerPill;
// Round pills to a reasonable number (e.g., max 2 pills for 200mg strength, or 1 for 400mg etc.)
// This part needs careful consideration for practicality vs precision.
// For this example, let's round to the nearest half pill for simplicity in calculation display.
pillsPerDose = Math.round(pillsPerDose * 2) / 2; // Round to nearest 0.5 pill
// Recalculate the actual mg dose based on rounded pills to ensure consistency
finalSingleDose = pillsPerDose * strengthPerPill;
// Final check: Ensure the recalculated finalSingleDose is still within the 5-10 mg/kg range
if (finalSingleDose 0) {
// If rounding down made it too low, potentially increase pills if feasible within max daily
// Or simply cap at the minimum recommended dose mg
finalSingleDose = minSingleDose;
pillsPerDose = Math.max(0.5, Math.round(finalSingleDose / strengthPerPill * 2) / 2); // Ensure at least 0.5 pill if weight implies dosage
finalSingleDose = pillsPerDose * strengthPerPill; // Recalculate mg based on potentially adjusted pills
}
if (finalSingleDose > maxSingleDose && pillsPerDose > 0) {
// If rounding up made it too high, potentially decrease pills if feasible
finalSingleDose = maxSingleDose;
pillsPerDose = Math.max(0.5, Math.round(finalSingleDose / strengthPerPill * 2) / 2);
finalSingleDose = pillsPerDose * strengthPerPill;
}
// Ensure max daily dose calculation is correct
var totalDailyIntake = finalSingleDose * (24 / frequency);
if (totalDailyIntake > maxDailyDose) {
// If the dose frequency makes the daily total exceed the max,
// we need to either reduce the single dose or warn the user.
// Reducing the single dose to fit the daily max:
var adjustedSingleDoseBasedOnDailyMax = maxDailyDose / (24 / frequency);
finalSingleDose = Math.max(minSingleDose, adjustedSingleDoseBasedOnDailyMax); // Ensure it's still at least the minimum
pillsPerDose = finalSingleDose / strengthPerPill;
pillsPerDose = Math.round(pillsPerDose * 2) / 2;
finalSingleDose = pillsPerDose * strengthPerPill;
// Update maxDailyDoseDiv text to reflect the calculated limit
maxDailyDoseDiv.textContent = maxDailyDose.toFixed(0) + " mg (Recommended Maximum)";
} else {
maxDailyDoseDiv.textContent = maxDailyDose.toFixed(0) + " mg";
}
// Display results
mainResultDiv.textContent = finalSingleDose.toFixed(0) + " mg";
singleDoseDiv.textContent = finalSingleDose.toFixed(0) + " mg";
pillsPerDoseDiv.textContent = pillsPerDose;
// Update Chart
updateChart(weightKg, frequency, strengthPerPill, finalSingleDose, maxDailyDose);
}
function resetCalculator() {
document.getElementById("weightKg").value = "70"; // Sensible default adult weight
document.getElementById("dosageForm").value = "200"; // Default to 200mg Advil Tablets
document.getElementById("frequency").value = "6"; // Default frequency
currentStrengthMg = 200; // Reset global variable
calculateDosage(); // Recalculate with defaults
}
function copyResults() {
var mainResult = document.getElementById("mainResult").textContent;
var singleDose = document.getElementById("singleDose").textContent;
var maxDailyDose = document.getElementById("maxDailyDose").textContent;
var pillsPerDose = document.getElementById("pillsPerDose").textContent;
var weightKg = document.getElementById("weightKg").value;
var strength = document.getElementById("dosageForm").options[document.getElementById("dosageForm").selectedIndex].text;
var frequency = document.getElementById("frequency").options[document.getElementById("frequency").selectedIndex].text;
var textToCopy = "Advil Dosage Calculation Results:\n\n";
textToCopy += "Input:\n";
textToCopy += "- Weight: " + weightKg + " kg\n";
textToCopy += "- Advil Strength: " + strength + "\n";
textToCopy += "- Frequency: " + frequency + "\n\n";
textToCopy += "Key Assumptions:\n";
textToCopy += "- Dosage Formula: 5-10 mg/kg per dose, max 40 mg/kg/day\n\n";
textToCopy += "Calculated Dosage:\n";
textToCopy += "- Recommended Single Dose: " + mainResult + "\n";
textToCopy += "- Single Dose (details): " + singleDose + "\n";
textToCopy += "- Max Daily Dose: " + maxDailyDose + "\n";
textToCopy += "- Pills Per Dose: " + pillsPerDose + "\n";
navigator.clipboard.writeText(textToCopy).then(function() {
alert("Results copied to clipboard!");
}, function(err) {
console.error('Could not copy text: ', err);
// Fallback for browsers that don't support navigator.clipboard
var textArea = document.createElement("textarea");
textArea.value = textToCopy;
textArea.style.position = "fixed"; // Avoid scrolling to bottom
document.body.appendChild(textArea);
textArea.focus();
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'successful' : 'unsuccessful';
console.log('Fallback: Copying text command was ' + msg);
alert("Results copied to clipboard!");
} catch (err) {
console.error('Fallback: Oops, unable to copy', err);
alert("Could not copy results. Please copy manually.");
}
document.body.removeChild(textArea);
});
}
// Chart Logic
var dosageChart;
function updateChart(weightKg, frequency, strengthPerPill, calculatedSingleDoseMg, calculatedMaxDailyDoseMg) {
var ctx = document.getElementById('dosageChart').getContext('2d');
// Clear previous chart instance if it exists
if (dosageChart) {
dosageChart.destroy();
}
var maxPossibleDosesPerDay = Math.floor(24 / frequency);
var totalDailyIntakeFromSingleDose = calculatedSingleDoseMg * maxPossibleDosesPerDay;
var dataSeries1 = []; // Single Dose mg
var dataSeries2 = []; // Max Daily Dose mg
var labels = [];
// Generate data points for visualization, e.g., from 10kg to 100kg
for (var w = 10; w <= 100; w += 10) {
labels.push(w + " kg");
var currentSingleDose = Math.max(w * 5, Math.min(w * 10, w * 7.5)); // Simplified calculation for chart data
// Adjust to nearest practical pill count
var currentPills = currentSingleDose / strengthPerPill;
currentPills = Math.round(currentPills * 2) / 2;
currentSingleDose = currentPills * strengthPerPill;
dataSeries1.push(currentSingleDose);
dataSeries2.push(w * 40); // Max daily dose based on weight * 40mg/kg
}
dosageChart = new Chart(ctx, {
type: 'line',
data: {
labels: labels,
datasets: [{
label: 'Recommended Single Dose (mg)',
data: dataSeries1,
borderColor: 'var(–primary-color)',
backgroundColor: 'rgba(0, 74, 153, 0.2)',
fill: true,
tension: 0.1
}, {
label: 'Maximum Daily Dose (mg)',
data: dataSeries2,
borderColor: 'var(–success-color)',
backgroundColor: 'rgba(40, 167, 69, 0.2)',
fill: true,
tension: 0.1
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
title: {
display: true,
text: 'Body Weight (kg)'
}
},
y: {
title: {
display: true,
text: 'Dosage (mg)'
},
beginAtZero: true
}
},
plugins: {
tooltip: {
callbacks: {
label: function(context) {
var label = context.dataset.label || '';
if (label) {
label += ': ';
}
if (context.parsed.y !== null) {
label += context.parsed.y + ' mg';
}
return label;
}
}
}
}
}
});
}
// Add a canvas element for the chart
var chartContainer = document.createElement('div');
chartContainer.innerHTML = '
Dosage vs. Weight Chart
This chart illustrates how recommended single dose and maximum daily dose change with body weight, based on standard guidelines.';
// Insert chart after the calculator results section or before the article
var calculatorWrapper = document.querySelector('.calculator-wrapper');
calculatorWrapper.parentNode.insertBefore(chartContainer, calculatorWrapper.nextSibling);
// Initial calculation and chart setup on page load
document.addEventListener("DOMContentLoaded", function() {
updateStrengthInfo(); // Set initial strength based on default select value
resetCalculator(); // Set default values and perform initial calculation
// Initial chart update using default values from resetCalculator()
var weightKg = parseFloat(document.getElementById("weightKg").value);
var frequency = parseInt(document.getElementById("frequency").value);
var strengthPerPill = currentStrengthMg;
var calculatedSingleDose = weightKg * 7.5; // Simplified for initial chart calc
var calculatedMaxDailyDose = weightKg * 40;
updateChart(weightKg, frequency, strengthPerPill, calculatedSingleDose, calculatedMaxDailyDose);
});
// Add event listener for input changes to trigger chart update indirectly via calculateDosage
document.getElementById("weightKg").addEventListener("input", calculateDosage);
document.getElementById("dosageForm").addEventListener("change", calculateDosage);
document.getElementById("frequency").addEventListener("change", calculateDosage);