Please enter valid positive numbers for all fields.
Infusion Pump Rate:0 mL/hr
Manual Drip Rate:0 gtts/min
Concentration:0 mcg/mL
Total Dose per Hour:0 mg/hr
function calculateDripRate() {
// Get values from DOM
var weight = parseFloat(document.getElementById('ptWeight').value);
var dose = parseFloat(document.getElementById('dose').value);
var drugMg = parseFloat(document.getElementById('drugAmount').value);
var volMl = parseFloat(document.getElementById('bagVolume').value);
var dropFactor = parseFloat(document.getElementById('dropFactor').value);
var errorDiv = document.getElementById('errorDisplay');
var resultDiv = document.getElementById('resultBox');
// Reset display
errorDiv.style.display = 'none';
resultDiv.style.display = 'none';
// Validation
if (isNaN(weight) || weight <= 0 ||
isNaN(dose) || dose <= 0 ||
isNaN(drugMg) || drugMg <= 0 ||
isNaN(volMl) || volMl <= 0) {
errorDiv.style.display = 'block';
return;
}
// Logic
// 1. Calculate Concentration in mcg/mL
// First get mg/mL, then multiply by 1000 to get mcg/mL
var concentrationMgPerMl = drugMg / volMl;
var concentrationMcgPerMl = concentrationMgPerMl * 1000;
// 2. Calculate Total Dose needed per minute (mcg/min)
var doseMcgPerMin = dose * weight;
// 3. Calculate Flow Rate in mL/min
var flowRateMlPerMin = doseMcgPerMin / concentrationMcgPerMl;
// 4. Calculate Flow Rate in mL/hr (Pump setting)
var flowRateMlPerHour = flowRateMlPerMin * 60;
// 5. Calculate Drop Rate (gtts/min) for manual gravity
// Formula: (mL/hr * drop factor) / 60
var gttsPerMin = (flowRateMlPerHour * dropFactor) / 60;
// 6. Calculate total mg per hour (for reference)
var mgPerHour = (doseMcgPerMin * 60) / 1000;
// Display Results
document.getElementById('resMlHr').innerHTML = flowRateMlPerHour.toFixed(1) + " mL/hr";
document.getElementById('resGtts').innerHTML = Math.round(gttsPerMin) + " gtts/min";
document.getElementById('resConc').innerHTML = concentrationMcgPerMl.toFixed(0) + " mcg/mL";
document.getElementById('resTotalDose').innerHTML = mgPerHour.toFixed(2) + " mg/hr";
resultDiv.style.display = 'block';
}
Understanding the IV Drip Rate (mcg/kg/min) Calculation
In critical care environments, precise medication delivery is paramount. Many potent vasoactive drugs, such as Dopamine, Dobutamine, Epinephrine, and Norepinephrine, are dosed based on the patient's body weight and time. The standard unit for these calculations is micrograms per kilogram per minute (mcg/kg/min).
This calculator bridges the gap between the ordered dose (what the doctor prescribes) and the machine settings (what the nurse programs into the pump).
Note: 1 mg = 1,000 mcg. Correct unit conversion is the most critical step in preventing medication errors.
The Formula Behind the Calculator
To convert a weight-based dose into an infusion rate (mL/hr), the calculation follows these logical steps:
Determine Total Dose Required per Minute: Patient Weight (kg) × Ordered Dose (mcg/kg/min) = Total mcg/min
Determine Drug Concentration: (Total Drug (mg) ÷ Total Volume (mL)) × 1000 = Concentration in mcg/mL
While most modern hospitals use electronic infusion pumps (measured in mL/hr), manual flow regulation using gravity requires calculating the drop rate (gtts/min). The "Drop Factor" refers to how many drops the tubing set generates per milliliter of fluid.
Microdrip (60 gtts/mL): Used for pediatrics or precise, slow infusions.
Macrodrip (10, 15, or 20 gtts/mL): Used for rapid fluid resuscitation or general adult IVs.
Common Medications Dosed in mcg/kg/min
This calculator is commonly used for:
Dopamine: Typically 2-20 mcg/kg/min. Used for hemodynamic support.
Dobutamine: Typically 2-20 mcg/kg/min. Used for heart failure.
Norepinephrine (Levophed): Often 0.01-3 mcg/kg/min (though sometimes dosed in mcg/min).
Nitroprusside (Nipride): 0.3-10 mcg/kg/min. Used for hypertensive crisis.
Disclaimer: This tool is for educational and verification purposes only. Always double-check calculations with hospital protocols and approved medical devices before administering medication.