Accurate medication dosing is critical in healthcare to ensure patient safety and treatment efficacy.
This calculator helps determine the correct volume of medication to administer based on patient weight,
the prescribed dosage rate, and the concentration of the available medication.
How it Works:
The calculation follows these steps:
Calculate Total Dose Needed:
This is found by multiplying the patient's weight (in kilograms) by the required dosage per kilogram.
Total Dose (mg) = Patient Weight (kg) × Dosage Required (mg/kg)
Calculate Volume to Administer:
Once the total dose in milligrams is known, we can determine the volume (in milliliters) of the medication
solution to administer. This is done by dividing the total dose by the concentration of the medication.
Volume to Administer (ml) = Total Dose (mg) / Medication Concentration (mg/ml)
Example Scenario:
Let's consider a patient weighing 60 kg who needs a medication at a rate of 10 mg/kg. The available medication
is supplied in a solution with a concentration of 25 mg/ml.
Step 1: Total Dose Needed
Total Dose = 60 kg × 10 mg/kg = 600 mg
Step 2: Volume to Administer
Volume = 600 mg / 25 mg/ml = 24 ml
Therefore, 24 ml of the medication solution should be administered to this patient.
Important Considerations:
Always double-check your calculations, especially in critical care situations.
Ensure you are using the correct units (kg for weight, mg for dose, mg/ml for concentration).
This calculator is a tool and should not replace professional medical judgment or established protocols.
Consult with a healthcare professional for specific medical advice.
function calculateDosage() {
var patientWeight = parseFloat(document.getElementById("patientWeight").value);
var dosagePerKg = parseFloat(document.getElementById("dosagePerKg").value);
var medicationConcentration = parseFloat(document.getElementById("medicationConcentration").value);
var dosageOutput = document.getElementById("dosageOutput");
// Clear previous results and error messages
dosageOutput.textContent = "–";
// Input validation
if (isNaN(patientWeight) || patientWeight <= 0) {
alert("Please enter a valid patient weight in kilograms (must be a positive number).");
return;
}
if (isNaN(dosagePerKg) || dosagePerKg <= 0) {
alert("Please enter a valid dosage required (must be a positive number).");
return;
}
if (isNaN(medicationConcentration) || medicationConcentration <= 0) {
alert("Please enter a valid medication concentration (must be a positive number).");
return;
}
// Calculation
var totalDose = patientWeight * dosagePerKg;
var volumeToAdminister = totalDose / medicationConcentration;
// Display result
dosageOutput.textContent = volumeToAdminister.toFixed(2) + " ml"; // Display with 2 decimal places for precision
}