Accurate medication dosage calculation is crucial in healthcare to ensure patient safety and therapeutic effectiveness. This calculator helps determine the correct amount of medication to administer based on patient weight and the medication's prescribed dosage and concentration.
How it Works:
The calculation involves several steps:
Calculate Total Dosage Required: The first step is to determine the total milligrams (or micrograms, grams) of medication the patient needs. This is typically calculated by multiplying the patient's weight by the prescribed dosage per kilogram.
Calculate Volume to Administer: Once the total dosage is known, we need to determine the volume of the medication solution that contains this dosage. This is done using the concentration of the medication provided (e.g., mg/mL).
Formula: Volume to Administer (mL) = Total Dosage (mg) / Medication Concentration (mg/mL)
Unit Conversions: It's important to handle unit conversions correctly. For example, if the prescribed dosage is in mcg/kg but the concentration is in mg/mL, you'll need to convert units to be consistent before calculating. This calculator handles common conversions for milligrams (mg), micrograms (mcg), and grams (g).
Use Cases:
This calculator is useful for:
Nurses and other healthcare professionals administering medications.
Pharmacists verifying dosages.
Medical students and trainees practicing dosage calculations.
Anyone needing to calculate medication doses based on weight.
Disclaimer: This calculator is for informational and educational purposes only. Always consult with a qualified healthcare professional and follow established medical protocols for medication administration. Do not rely solely on this calculator for patient care decisions.
function calculateDosage() {
var patientWeight = parseFloat(document.getElementById("patientWeight").value);
var medicationDosagePerKg = parseFloat(document.getElementById("medicationDosagePerKg").value);
var medicationConcentrationUnit = document.getElementById("medicationConcentrationUnit").value;
var medicationConcentrationValue = parseFloat(document.getElementById("medicationConcentrationValue").value);
var medicationFormulation = document.getElementById("medicationFormulation").value;
var resultElement = document.getElementById("calculatedDosage");
var volumeResultElement = document.getElementById("calculatedVolume");
resultElement.innerText = "";
volumeResultElement.innerText = "";
// Input validation
if (isNaN(patientWeight) || patientWeight <= 0) {
resultElement.innerText = "Please enter a valid patient weight.";
return;
}
if (isNaN(medicationDosagePerKg) || medicationDosagePerKg < 0) {
resultElement.innerText = "Please enter a valid medication dosage per kg.";
return;
}
if (isNaN(medicationConcentrationValue) || medicationConcentrationValue 0) {
volumeToAdministerMl = totalDosageMg / concentrationMgPerMl;
}
// Display results
var formattedTotalDosage = totalDosageMg.toFixed(2);
var formattedVolume = volumeToAdministerMl.toFixed(2);
// Determine correct unit for total dosage display based on original input
var dosageUnit = ";
if (medicationFormulation === 'mg') dosageUnit = 'mg';
else if (medicationFormulation === 'mcg') dosageUnit = 'mcg';
else if (medicationFormulation === 'g') dosageUnit = 'g';
// Adjust displayed total dosage back to original unit if necessary for clarity
if (medicationFormulation === 'mcg') formattedTotalDosage = (totalDosageMg * 1000).toFixed(2);
else if (medicationFormulation === 'g') formattedTotalDosage = (totalDosageMg / 1000).toFixed(2);
resultElement.innerText = "Total Dosage Required: " + formattedTotalDosage + " " + dosageUnit;
volumeResultElement.innerText = "Volume to Administer: " + formattedVolume + " mL";
}