.iv-calc-row { margin-bottom: 20px; }
.iv-calc-label { display: block; font-weight: 600; margin-bottom: 8px; font-size: 16px; }
.iv-calc-input, .iv-calc-select { width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; box-sizing: border-box; }
.iv-calc-btn { background-color: #0056b3; color: white; padding: 15px 20px; border: none; border-radius: 4px; cursor: pointer; font-size: 18px; font-weight: bold; width: 100%; transition: background 0.3s; }
.iv-calc-btn:hover { background-color: #004494; }
.iv-result-box { margin-top: 25px; padding: 20px; background-color: #e8f4fd; border-left: 5px solid #0056b3; border-radius: 4px; display: none; }
.iv-metric { font-size: 24px; font-weight: bold; color: #0056b3; }
.iv-unit { font-size: 16px; color: #555; font-weight: normal; }
.iv-summary { margin-top: 10px; font-size: 15px; line-height: 1.5; }
.iv-error { color: #d32f2f; font-weight: bold; display: none; margin-top: 10px; }
function calculateIVRate() {
var volumeInput = document.getElementById('iv_volume');
var timeInput = document.getElementById('iv_time');
var factorInput = document.getElementById('iv_drop_factor');
var resultBox = document.getElementById('iv_result_display');
var errorMsg = document.getElementById('iv_error_msg');
var volume = parseFloat(volumeInput.value);
var timeHours = parseFloat(timeInput.value);
var dropFactor = parseFloat(factorInput.value);
// Validation logic
if (isNaN(volume) || isNaN(timeHours) || isNaN(dropFactor) || volume <= 0 || timeHours <= 0) {
errorMsg.style.display = 'block';
resultBox.style.display = 'none';
return;
}
errorMsg.style.display = 'none';
// Calculation Logic
// 1. Calculate mL/hr (Flow Rate)
var mlPerHour = volume / timeHours;
// 2. Calculate gtt/min (Drip Rate)
// Formula: (Volume (mL) * Drop Factor (gtt/mL)) / Time (minutes)
var timeMinutes = timeHours * 60;
var dropsPerMinute = (volume * dropFactor) / timeMinutes;
// Formatting Results
// Standard practice: mL/hr is usually rounded to 1 decimal place for pumps, or whole number.
// Drops per minute must be a whole number (you can't count partial drops).
document.getElementById('res_ml_hr').innerText = mlPerHour.toFixed(1);
document.getElementById('res_gtt_min').innerText = Math.round(dropsPerMinute);
// Update Summary
document.getElementById('sum_vol').innerText = volume;
document.getElementById('sum_time').innerText = timeHours;
document.getElementById('sum_factor').innerText = dropFactor;
document.getElementById('sum_rate').innerText = mlPerHour.toFixed(1);
document.getElementById('sum_drops').innerText = Math.round(dropsPerMinute);
resultBox.style.display = 'block';
}
IV Infusion Rate Calculator
For 30 minutes, enter 0.5
10 gtt/mL (Macrodrip – Standard)
15 gtt/mL (Macrodrip)
20 gtt/mL (Macrodrip)
60 gtt/mL (Microdrip/Pediatric)
Please enter valid positive numbers for Volume and Time.
Electronic Pump Rate
0 mL/hr
Manual Gravity Drip Rate
0 gtt/min
Clinical Summary: To infuse 0 mL over 0 hours using a 0 gtt/mL tubing set, set the pump to 0 mL/hr or adjust the manual roller clamp to approximately 0 drops per minute.
Understanding IV Infusion Rate Calculations
Accurate dosage calculations for intravenous (IV) therapy are a critical skill for nurses and healthcare providers. Ensuring the correct infusion rate prevents complications such as fluid overload or under-dosing. This calculator determines two primary metrics used in clinical settings: the flow rate (mL/hr) for electronic infusion pumps and the drip rate (gtt/min) for manual gravity flow.
The Formulas
There are two main formulas utilized depending on the equipment available:
1. Flow Rate (for Pumps)
Rate (mL/hr) = Total Volume (mL) ÷ Time (Hours)
2. Drip Rate (for Gravity Tubing)
Drip Rate (gtt/min) = (Total Volume (mL) × Drop Factor (gtt/mL)) ÷ Time (Minutes)
Input Definitions
- Total Volume (mL): The amount of fluid prescribed to be infused (e.g., 1000 mL of Normal Saline).
- Time (Hours): The duration over which the infusion should take place. If the order is in minutes, convert to hours (e.g., 30 minutes = 0.5 hours).
- Drop Factor (gtt/mL): This number is found on the packaging of the IV tubing set. It indicates how many drops it takes to equal 1 milliliter.
- Macrodrip (10, 15, 20 gtt/mL): Used for general adult IV therapy and rapid infusion.
- Microdrip (60 gtt/mL): Used for pediatrics or precise medication administration. Note that with a 60 gtt/mL set, the drops per minute equal the mL per hour.
Example Calculation
Scenario: A doctor orders 1000 mL of Lactated Ringer's to be infused over 8 hours using tubing with a drop factor of 15 gtt/mL.
- Calculate mL/hr: 1000 mL ÷ 8 hours = 125 mL/hr.
- Calculate gtt/min: First, convert hours to minutes (8 × 60 = 480 minutes).
- Apply Formula: (1000 mL × 15 gtt/mL) ÷ 480 min = 15,000 ÷ 480 = 31.25 gtt/min.
- Result: Since you cannot count partial drops, you would round to the nearest whole number: 31 gtt/min.
Why Precision Matters
While electronic pumps manage the flow rate automatically based on the mL/hr input, mechanical failure or lack of equipment requires the nurse to manually calculate and count drops. Errors in calculation can lead to infiltration, phlebitis, or systemic toxicity if potent medications are infused too rapidly. Always double-check calculations and verify the drop factor of the tubing being used.