.iv-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #fff;
padding: 20px;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.iv-calc-box {
background: #f8f9fa;
border: 1px solid #e9ecef;
padding: 25px;
border-radius: 8px;
margin-bottom: 30px;
}
.iv-calc-row {
display: flex;
flex-wrap: wrap;
margin-bottom: 15px;
gap: 15px;
}
.iv-calc-col {
flex: 1;
min-width: 200px;
}
.iv-calc-label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
}
.iv-calc-input {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.iv-calc-input:focus {
border-color: #007bff;
outline: none;
}
.iv-calc-btn {
background-color: #007bff;
color: white;
padding: 12px 24px;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
font-weight: 600;
width: 100%;
transition: background-color 0.2s;
}
.iv-calc-btn:hover {
background-color: #0056b3;
}
.iv-result-box {
margin-top: 20px;
padding: 20px;
background-color: #e8f4fd;
border-left: 5px solid #007bff;
display: none;
}
.iv-result-title {
font-size: 14px;
text-transform: uppercase;
letter-spacing: 1px;
color: #555;
margin-bottom: 10px;
}
.iv-result-value {
font-size: 32px;
font-weight: bold;
color: #007bff;
margin-bottom: 5px;
}
.iv-result-sub {
font-size: 18px;
color: #495057;
}
.iv-content h2 {
color: #2c3e50;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 30px;
}
.iv-content h3 {
color: #34495e;
margin-top: 20px;
}
.iv-content ul {
line-height: 1.6;
color: #444;
}
.iv-content p {
line-height: 1.6;
color: #444;
margin-bottom: 15px;
}
.formula-box {
background: #f1f3f5;
padding: 15px;
border-radius: 4px;
font-family: monospace;
margin: 15px 0;
border: 1px dashed #adb5bd;
}
function calculateIVFlowRate() {
// Get input values
var volume = document.getElementById("totalVolume").value;
var dropFactor = document.getElementById("dropFactor").value;
var hours = document.getElementById("timeHours").value;
var minutes = document.getElementById("timeMinutes").value;
var resultBox = document.getElementById("ivResult");
// Validate inputs
if (volume === "" || (hours === "" && minutes === "")) {
alert("Please enter Volume and Infusion Time.");
return;
}
// Convert strings to numbers
var volNum = parseFloat(volume);
var factorNum = parseFloat(dropFactor);
var hrsNum = hours === "" ? 0 : parseFloat(hours);
var minsNum = minutes === "" ? 0 : parseFloat(minutes);
// Calculate total time in minutes
var totalMinutes = (hrsNum * 60) + minsNum;
// Prevent division by zero
if (totalMinutes <= 0) {
alert("Total infusion time must be greater than zero.");
return;
}
// Calculate gtt/min (Drops per minute)
// Formula: (Volume (mL) * Drop Factor (gtt/mL)) / Time (min)
var flowRateGtt = (volNum * factorNum) / totalMinutes;
// Round to nearest whole number for drops (cannot have partial drops)
var roundedGtt = Math.round(flowRateGtt);
// Calculate mL/hr for infusion pumps
var mlPerHour = (volNum / totalMinutes) * 60;
// Update Results
document.getElementById("gttResult").innerHTML = roundedGtt + " gtt/min";
document.getElementById("mlHrResult").innerHTML = mlPerHour.toFixed(1) + " mL/hr";
// Show result box
resultBox.style.display = "block";
}
Understanding the IV Flow Rate Formula
Accurately calculating intravenous (IV) flow rates is a critical skill in nursing and healthcare. Whether you are using a manual gravity drip or an electronic infusion pump, ensuring the correct volume of fluid is delivered over a specific period is essential for patient safety.
The Core Formula
To calculate the drip rate in drops per minute (gtt/min), you need three pieces of information:
- Total Volume: The amount of liquid to be infused (in milliliters/mL).
- Drop Factor: The number of drops it takes to make 1 mL (found on the IV tubing packaging).
- Time: The total duration for the infusion (converted to minutes).
Flow Rate (gtt/min) = (Total Volume (mL) × Drop Factor (gtt/mL)) ÷ Time (minutes)
Common Drop Factors
The "drop factor" or calibration is specific to the tubing used. It is measured in gtt/mL (guttae per milliliter).
- Macrodrip (10, 15, or 20 gtt/mL): Used for delivering large volumes or fast rates. Standard blood tubing is often 10 gtt/mL.
- Microdrip (60 gtt/mL): Used for precise delivery of small volumes, such as in pediatrics or potent medication administration. Note that for 60 gtt/mL tubing, the gtt/min rate equals the mL/hr rate.
Calculation Example
Let's say a doctor orders 1000 mL of Normal Saline to be infused over 8 hours. The IV tubing set you are using has a drop factor of 15 gtt/mL.
Step 1: Convert hours to minutes.
8 hours × 60 minutes = 480 minutes.
Step 2: Apply the formula.
(1000 mL × 15 gtt/mL) ÷ 480 minutes
15,000 ÷ 480 = 31.25
Step 3: Round to the nearest whole number.
Since you cannot count a fraction of a drop, you would regulate the IV to flow at 31 gtt/min (drops per minute).
Calculating for Infusion Pumps (mL/hr)
If you are using an electronic pump, you generally need to program the rate in milliliters per hour (mL/hr) rather than counting drops.
Flow Rate (mL/hr) = Total Volume (mL) ÷ Time (hours)
Using the example above: 1000 mL ÷ 8 hours = 125 mL/hr.