.iv-calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #fff;
color: #333;
}
.iv-calc-container {
background: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 25px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.iv-calc-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.iv-form-group {
margin-bottom: 20px;
}
.iv-form-label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #495057;
}
.iv-input-row {
display: flex;
gap: 15px;
}
.iv-input-col {
flex: 1;
}
.iv-input {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.2s;
}
.iv-input:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 0 3px rgba(0,123,255,0.1);
}
.iv-btn {
display: block;
width: 100%;
background-color: #0056b3;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: 600;
border-radius: 4px;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.iv-btn:hover {
background-color: #004494;
}
.iv-result-box {
margin-top: 25px;
padding: 20px;
background-color: #e8f4fd;
border: 1px solid #b8daff;
border-radius: 6px;
display: none;
}
.iv-result-item {
display: flex;
justify-content: space-between;
align-items: center;
padding: 10px 0;
border-bottom: 1px solid #d6e9fc;
}
.iv-result-item:last-child {
border-bottom: none;
}
.iv-result-label {
font-weight: 600;
color: #004085;
}
.iv-result-value {
font-size: 20px;
font-weight: 700;
color: #0056b3;
}
.iv-content-section h2 {
color: #2c3e50;
margin-top: 30px;
font-size: 22px;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
}
.iv-content-section p {
line-height: 1.6;
margin-bottom: 15px;
color: #4a4a4a;
}
.iv-content-section ul {
margin-bottom: 20px;
padding-left: 20px;
}
.iv-content-section li {
margin-bottom: 8px;
line-height: 1.6;
}
.iv-table {
width: 100%;
border-collapse: collapse;
margin: 20px 0;
}
.iv-table th, .iv-table td {
border: 1px solid #dee2e6;
padding: 12px;
text-align: left;
}
.iv-table th {
background-color: #e9ecef;
font-weight: 600;
}
.iv-helper-text {
font-size: 12px;
color: #6c757d;
margin-top: 5px;
}
function calculateFlowRate() {
// Get inputs
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('ivDropFactor').value);
// Handle empty inputs or NaNs by defaulting to 0
if (isNaN(hours)) hours = 0;
if (isNaN(minutes)) minutes = 0;
// Validation
if (isNaN(volume) || volume <= 0) {
alert("Please enter a valid total volume greater than 0.");
return;
}
var totalMinutes = (hours * 60) + minutes;
if (totalMinutes 0) {
secPerDrop = 60 / gttPerMin;
}
// Formatting Results
var displayMlHr = mlPerHour.toFixed(1);
if (displayMlHr.endsWith('.0')) {
displayMlHr = Math.round(mlPerHour);
}
var displayGtt = Math.round(gttPerMin); // Drops must be whole numbers usually
var displaySecDrop = secPerDrop.toFixed(1);
// Update DOM
document.getElementById('resMlHr').innerHTML = displayMlHr + " mL/hr";
document.getElementById('resGttMin').innerHTML = displayGtt + " gtt/min";
// If the rate is too fast to count manually or too slow
if (displayGtt > 0) {
document.getElementById('resSecDrop').innerHTML = "1 drop every " + displaySecDrop + " sec";
} else {
document.getElementById('resSecDrop').innerHTML = "-";
}
// Show result box
document.getElementById('ivResult').style.display = 'block';
}
Infusion Flow Rate Calculator
Hours
Minutes
10 gtt/mL (Macrodrip)
15 gtt/mL (Macrodrip)
20 gtt/mL (Macrodrip)
60 gtt/mL (Microdrip)
Check your IV tubing package for this value.
Volumetric Rate:
0 mL/hr
Drip Rate:
0 gtt/min
Drop Interval:
0 sec/drop
How to Calculate Flow Rate of Infusion
Correctly calculating the flow rate of an intravenous (IV) infusion is a critical skill in nursing and healthcare. It ensures that patients receive the prescribed volume of medication or fluid over the correct period of time. This guide explains the mathematics behind the calculator and how to perform these calculations manually.
The Two Main IV Calculation Formulas
There are two primary ways to measure IV flow rate, depending on whether you are using an electronic infusion pump or manual gravity tubing.
1. Milliliters per Hour (mL/hr)
This formula is generally used for electronic infusion pumps which are programmed to deliver a specific volume per hour.
Formula: Total Volume (mL) ÷ Total Time (hours) = Flow Rate (mL/hr)
2. Drops per Minute (gtt/min)
This formula is used for manual gravity IV lines where the nurse counts the drops falling in the drip chamber. To calculate this, you must know the drop factor of the tubing.
Formula: (Total Volume (mL) × Drop Factor (gtt/mL)) ÷ Total Time (minutes) = Flow Rate (gtt/min)
Understanding the Drop Factor
The drop factor is the number of drops (gtt) it takes to equal 1 milliliter (mL) of fluid. This is determined by the width of the tubing needle in the drip chamber and is printed on the IV tubing packaging.
| Tubing Type | Common Drop Factors | Clinical Use |
|---|---|---|
| Macrodrip | 10, 15, or 20 gtt/mL | Used for general adult fluids, rapid fluid resuscitation, or thick fluids. |
| Microdrip | 60 gtt/mL | Used for pediatrics, elderly patients, or when precise medication amounts are needed. |
Calculation Example
Scenario: A doctor orders 1,000 mL of Normal Saline to infuse over 8 hours. The available IV tubing has a drop factor of 15 gtt/mL.
Step 1: Calculate mL/hr (Pump Setting)
- Volume: 1,000 mL
- Time: 8 hours
- Calculation: 1000 ÷ 8 = 125 mL/hr
Step 2: Calculate gtt/min (Gravity Flow)
- Convert hours to minutes: 8 hours × 60 = 480 minutes.
- Apply Formula: (1000 mL × 15 gtt/mL) ÷ 480 min
- Calculation: 15,000 ÷ 480 = 31.25
- Result: Round to the nearest whole number, 31 gtt/min.
Tips for Accurate IV Administration
- Always Round Correctly: For drops per minute, you cannot count a fraction of a drop, so always round to the nearest whole number. For pumps, some can handle decimals (e.g., 125.5 mL/hr), but many require whole numbers.
- Monitor the Patient: Even with correct calculations, factors like vein position, tubing kinks, or patient movement can alter the actual flow rate.
- Double Check High-Risk Meds: Heparin, insulin, and cardiac medications often require a second nurse verification for calculations.