Calculating Iv Flow Rates

Hours Minutes

10 (Macro – standard) 15 (Macro – standard) 20 (Macro – standard) 60 (Micro – pediatric)

Calculation Results:

Infusion Rate: mL/hr

Drip Rate: gtt/min (drops per minute)

Please enter valid positive numbers for volume and time.

How to Calculate IV Flow Rates

Calculating the correct intravenous (IV) flow rate is a critical skill for healthcare professionals to ensure patients receive medications and fluids safely. Depending on whether you are using an electronic infusion pump or gravity drip, you will need to calculate mL/hr or gtt/min.

The Basic Formulas

There are two primary formulas used in clinical settings:

1. mL per Hour (mL/hr): Used for electronic pumps.
   Formula: Total Volume (mL) ÷ Total Time (hr) = mL/hr
2. Drops per Minute (gtt/min): Used for gravity infusions.
   Formula: [Total Volume (mL) × Drop Factor (gtt/mL)] ÷ Time (minutes) = gtt/min

Understanding the Drop Factor

The "Drop Factor" is the number of drops it takes to make up 1 mL of fluid. This is determined by the IV tubing manufacturer and is printed on the tubing package. Common sizes include:

• Macro-drip: 10, 15, or 20 gtt/mL (typically used for adults).
• Micro-drip: 60 gtt/mL (typically used for pediatric or neonatal care).

Example Calculation

Scenario: A physician orders 1000 mL of Normal Saline to be infused over 8 hours. The tubing has a drop factor of 15 gtt/mL.

• Step 1 (mL/hr): 1000 mL ÷ 8 hr = 125 mL/hr
• Step 2 (gtt/min): (1000 mL × 15) ÷ (8 × 60 minutes) = 15,000 ÷ 480 = 31.25 (rounded to 31 gtt/min)

Medical Disclaimer: This calculator is for educational purposes only. Always double-check calculations according to your facility's protocols and pharmaceutical guidelines before administering any medication.