IV Flow Rate & Infusion Calculator
Calculate mL/hr and Drops Per Minute (gtt/min) for IV Therapy
Infusion Rate
Drip Rate
Understanding Medication Flow Rate Calculations
In clinical nursing and medical practice, calculating the correct IV flow rate is critical for patient safety. Whether you are using an infusion pump or setting a manual gravity drip, these formulas ensure the patient receives the prescribed dose of medication over the correct period.
1. How to Calculate mL/hr
This calculation is primarily used when setting an electronic infusion pump. The pump requires a rate in milliliters per hour.
Formula: Total Volume (mL) ÷ Total Time (hours) = mL/hr
2. How to Calculate Drip Rate (gtt/min)
The drip rate is used for manual IV administration where you count the number of drops falling in the drip chamber per minute. You must know the "Drop Factor" of the IV tubing set (found on the packaging).
Formula: [Total Volume (mL) × Drop Factor (gtt/mL)] ÷ Total Time (minutes) = gtt/min
Realistic Practice 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.
- Infusion Rate: 1,000 mL ÷ 8 hours = 125 mL/hr
- Drip Rate: (1,000 mL × 15 gtt/mL) ÷ (8 hours × 60 minutes) = 31.25 (31) gtt/min
Standard Drop Factors
| Tubing Type | Standard Drop Factor |
|---|---|
| Macro-drip | 10, 15, or 20 gtt/mL |
| Micro-drip (Pediatric) | 60 gtt/mL |