Ml/hr Rate Calculator

mL/hr Infusion Rate Calculator

Hours Minutes

Standard: Macrodrip (10, 15, 20), Microdrip (60)

Infusion Rate

0 mL/hr

function calculateInfusionRate() { var volume = parseFloat(document.getElementById('totalVolume').value); var duration = parseFloat(document.getElementById('timeDuration').value); var unit = document.getElementById('timeUnit').value; var dropFactor = parseFloat(document.getElementById('dropFactor').value); var resultArea = document.getElementById('mlResultArea'); var mlOutput = document.getElementById('mlRateOutput'); var gttOutput = document.getElementById('gttRateOutput'); if (isNaN(volume) || isNaN(duration) || volume <= 0 || duration 0) { var gttPerMin = (volume * dropFactor) / timeInMinutes; gttOutput.innerText = "Drip Rate: " + Math.round(gttPerMin) + " gtt/min"; gttOutput.style.display = "block"; } else { gttOutput.style.display = "none"; } resultArea.style.display = "block"; }

Understanding the mL/hr Rate Calculation

In clinical settings, accurately determining the infusion rate of intravenous (IV) fluids or medications is critical for patient safety. The mL/hr rate calculator simplifies the process of converting a prescribed volume and time into a precise flow rate for use with infusion pumps.

The mL/hr Formula

To find the milliliters per hour (mL/hr) rate, use the following fundamental equation:

Rate (mL/hr) = Total Volume (mL) ÷ Total Time (hr)

How to Calculate IV Drip Rates (gtt/min)

If you are using manual gravity tubing instead of an automated pump, you need to calculate the drops per minute (gtt/min). This requires the "Drop Factor," which is the number of drops it takes to equal 1 mL (usually found on the IV tubing packaging).

Drip Rate (gtt/min) = [Volume (mL) × Drop Factor (gtt/mL)] ÷ Time (min)

Practical Examples

• Standard Hydration: If a doctor orders 1,000 mL of Normal Saline to be infused over 8 hours, the calculation is 1000 ÷ 8 = 125 mL/hr.
• Antibiotic Bolus: If a patient needs 100 mL of an antibiotic over 30 minutes, first convert 30 minutes to 0.5 hours. Then, 100 ÷ 0.5 = 200 mL/hr.
• Drip Rate Calculation: Using the 1,000 mL over 8 hours (480 minutes) scenario with a 15 gtt/mL macro-drip set: (1000 × 15) ÷ 480 = 31.25 gtt/min (rounded to 31 gtt/min).

Common Drop Factors

Tubing Type	Drop Factor (gtt/mL)
Microdrip (Pediatric)	60 gtt/mL
Macrodrip (Standard)	10, 15, or 20 gtt/mL

Important Note: Always double-check calculations according to your facility's protocol. This tool is for educational purposes and should not replace professional clinical judgment or institutional policy.