Check the packaging of your IV tubing set for this number.
IV Drip Rate
0 gtt/min
Drops per minute
Infusion Rate
0 mL/hr
Milliliters per hour
How to Calculate IV Drip Rate
The IV Drip Rate Calculator allows nursing students and medical professionals to determine the correct flow rate for intravenous fluids. This calculation ensures that the prescribed volume of fluid is delivered over the specific time frame required by the physician.
The Formula
To calculate the drip rate in drops per minute (gtt/min), you need three variables: the total volume of fluid, the drop factor of the tubing, and the total time in minutes.
Drip Rate (gtt/min) = (Total Volume (mL) × Drop Factor (gtt/mL)) / Time (minutes)
If your time is given in hours, remember to convert it to minutes first:
Time (minutes) = Hours × 60
Understanding Drop Factors (Calibration)
The "Drop Factor" refers to how many drops it takes to equal 1 milliliter (mL) of fluid. This is determined by the width of the tubing needle and is printed on the IV set packaging. It is essential to select the correct factor for accurate dosing.
Type
Drop Factor (gtt/mL)
Usage Scenarios
Macrodrip
10, 15, or 20
Used for general IV fluid administration, larger volumes, and fast rates.
Microdrip
60
Used for precise medication administration, pediatrics, or slow flow rates. Note: 60 gtt/min = 60 mL/hr.
Example Calculation
Let's say a doctor prescribes 1,000 mL of Normal Saline to be infused over 8 hours. The tubing set you have available is a standard macro set with a drop factor of 15 gtt/mL.
Apply the formula: (1000 mL × 15 gtt/mL) / 480 minutes
Calculate: 15,000 / 480 = 31.25
Round: Since you cannot count a fraction of a drop, round to the nearest whole number: 31 gtt/min.
Why is this calculation important?
Administering fluids too fast (fluid overload) can lead to heart failure or pulmonary edema, while administering them too slowly can result in inadequate fluid resuscitation or ineffective medication therapy. Always verify calculations and check the pump or manual flow rate against a watch.
function calculateDripRate() {
// 1. Get input values
var volume = parseFloat(document.getElementById('ivVolume').value);
var hours = parseFloat(document.getElementById('ivHours').value);
var minutes = parseFloat(document.getElementById('ivMinutes').value);
var dropFactor = parseFloat(document.getElementById('dropFactor').value);
// 2. Handle empty or NaN inputs for time
if (isNaN(hours)) hours = 0;
if (isNaN(minutes)) minutes = 0;
// 3. Validation
var hasError = false;
if (isNaN(volume) || volume <= 0) {
alert("Please enter a valid Total Volume greater than 0.");
hasError = true;
}
var totalMinutes = (hours * 60) + minutes;
if (!hasError && totalMinutes <= 0) {
alert("Please enter a valid Time Duration greater than 0.");
hasError = true;
}
if (hasError) {
document.getElementById('resultsArea').style.display = 'none';
return;
}
// 4. Calculation Logic
// Formula: (Volume * Drop Factor) / Time in Minutes
var gttPerMin = (volume * dropFactor) / totalMinutes;
// Secondary Metric: mL per hour
var mlPerHour = volume / (totalMinutes / 60);
// 5. Display Results
var resultDiv = document.getElementById('resultsArea');
var gttDisplay = document.getElementById('resultGtt');
var mlDisplay = document.getElementById('resultMlHr');
// Round gtt to nearest whole number (standard nursing practice)
gttDisplay.innerHTML = Math.round(gttPerMin) + " gtt/min";
// Round mL/hr to 1 decimal place
mlDisplay.innerHTML = mlPerHour.toFixed(1) + " mL/hr";
// Show the results container
resultDiv.style.display = 'block';
}