Calculating Medication Drip Rates

IV Medication Drip Rate Calculator

Calculate GTT/Min and Flow Rate for Medical Administration

Hours Minutes
10 gtt/mL (Macro drip) 15 gtt/mL (Macro drip) 20 gtt/mL (Macro drip) 60 gtt/mL (Micro drip)
Drip Rate 0 drops / minute
Flow Rate 0 mL / hour

How to Calculate IV Drip Rates

In clinical settings, calculating the intravenous (IV) drip rate is critical for ensuring patient safety and therapeutic efficacy. This calculation determines how many drops per minute (gtt/min) must be administered through manual gravity infusion to deliver the prescribed volume over a specific time frame.

The Formula for IV Drip Rates

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

Key Components Explained

  • Total Volume: The total amount of fluid or medication to be infused, measured in milliliters (mL).
  • Time: The duration of the infusion. If the order is in hours, multiply by 60 to convert to minutes.
  • Drop Factor: This is determined by the administration set being used. Standard "Macro" sets are usually 10, 15, or 20 gtt/mL. "Micro" sets used for pediatric or high-precision dosing are always 60 gtt/mL.

Clinical Example

Scenario: A doctor orders 1,000 mL of Normal Saline to be infused over 8 hours. You are using a macro-drip set with a drop factor of 15 gtt/mL.

  1. Convert hours to minutes: 8 hours × 60 = 480 minutes.
  2. Divide Volume by Time: 1,000 mL / 480 minutes ≈ 2.083 mL/min.
  3. Multiply by Drop Factor: 2.083 × 15 = 31.25.
  4. Result: Approximately 31 drops per minute.
Important Clinical Note: Always double-check calculations with a colleague. This calculator is for educational purposes and should not be the sole basis for medication administration. Always follow your facility's specific protocols and cross-reference with pump settings.
function calculateDripRate() { var volume = parseFloat(document.getElementById("iv_volume").value); var timeVal = parseFloat(document.getElementById("iv_time").value); var timeUnit = document.getElementById("iv_time_unit").value; var dropFactor = parseFloat(document.getElementById("iv_drop_factor").value); var resultBox = document.getElementById("iv_result_box"); if (isNaN(volume) || isNaN(timeVal) || volume <= 0 || timeVal <= 0) { alert("Please enter valid positive numbers for volume and time."); return; } var timeInMinutes; var timeInHours; if (timeUnit === "hours") { timeInMinutes = timeVal * 60; timeInHours = timeVal; } else { timeInMinutes = timeVal; timeInHours = timeVal / 60; } // GTT/Min Formula: (Volume / Time in Minutes) * Drop Factor var gttPerMin = (volume / timeInMinutes) * dropFactor; // mL/hr Formula: Volume / Time in Hours var mlPerHour = volume / timeInHours; // Display results document.getElementById("res_gtt").innerText = Math.round(gttPerMin); document.getElementById("res_mlhr").innerText = mlPerHour.toFixed(1); resultBox.style.display = "block"; }

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